for Journals by Title or ISSN
for Articles by Keywords
help

Publisher: Elsevier   (Total: 3030 journals)

 A  B  C  D  E  F  G  H  I  J  K  L  M  N  O  P  Q  R  S  T  U  V  W  X  Y  Z  

        1 2 3 4 5 6 7 8 | Last   [Sort by number of followers]   [Restore default list]

Showing 1 - 200 of 3030 Journals sorted alphabetically
AASRI Procedia     Open Access   (Followers: 15)
Academic Pediatrics     Hybrid Journal   (Followers: 20, SJR: 1.402, h-index: 51)
Academic Radiology     Hybrid Journal   (Followers: 16, SJR: 1.008, h-index: 75)
Accident Analysis & Prevention     Partially Free   (Followers: 79, SJR: 1.109, h-index: 94)
Accounting Forum     Hybrid Journal   (Followers: 22, SJR: 0.612, h-index: 27)
Accounting, Organizations and Society     Hybrid Journal   (Followers: 27, SJR: 2.515, h-index: 90)
Achievements in the Life Sciences     Open Access   (Followers: 4)
Acta Anaesthesiologica Taiwanica     Open Access   (Followers: 5, SJR: 0.338, h-index: 19)
Acta Astronautica     Hybrid Journal   (Followers: 303, SJR: 0.726, h-index: 43)
Acta Automatica Sinica     Full-text available via subscription   (Followers: 3)
Acta Biomaterialia     Hybrid Journal   (Followers: 25, SJR: 2.02, h-index: 104)
Acta Colombiana de Cuidado Intensivo     Full-text available via subscription  
Acta de Investigación Psicológica     Open Access   (Followers: 2)
Acta Ecologica Sinica     Open Access   (Followers: 8, SJR: 0.172, h-index: 29)
Acta Haematologica Polonica     Free   (SJR: 0.123, h-index: 8)
Acta Histochemica     Hybrid Journal   (Followers: 3, SJR: 0.604, h-index: 38)
Acta Materialia     Hybrid Journal   (Followers: 196, SJR: 3.683, h-index: 202)
Acta Mathematica Scientia     Full-text available via subscription   (Followers: 5, SJR: 0.615, h-index: 21)
Acta Mechanica Solida Sinica     Full-text available via subscription   (Followers: 9, SJR: 0.442, h-index: 21)
Acta Oecologica     Hybrid Journal   (Followers: 9, SJR: 0.915, h-index: 53)
Acta Otorrinolaringologica (English Edition)     Full-text available via subscription   (Followers: 1)
Acta Otorrinolaringológica Española     Full-text available via subscription   (Followers: 3, SJR: 0.311, h-index: 16)
Acta Pharmaceutica Sinica B     Open Access   (Followers: 2)
Acta Poética     Open Access   (Followers: 4)
Acta Psychologica     Hybrid Journal   (Followers: 21, SJR: 1.365, h-index: 73)
Acta Sociológica     Open Access  
Acta Tropica     Hybrid Journal   (Followers: 5, SJR: 1.059, h-index: 77)
Acta Urológica Portuguesa     Open Access  
Actas Dermo-Sifiliograficas     Full-text available via subscription   (Followers: 4)
Actas Dermo-Sifiliográficas (English Edition)     Full-text available via subscription   (Followers: 3)
Actas Urológicas Españolas     Full-text available via subscription   (Followers: 3, SJR: 0.383, h-index: 19)
Actas Urológicas Españolas (English Edition)     Full-text available via subscription   (Followers: 2)
Actualites Pharmaceutiques     Full-text available via subscription   (Followers: 5, SJR: 0.141, h-index: 3)
Actualites Pharmaceutiques Hospitalieres     Full-text available via subscription   (Followers: 4, SJR: 0.112, h-index: 2)
Acupuncture and Related Therapies     Hybrid Journal   (Followers: 4)
Ad Hoc Networks     Hybrid Journal   (Followers: 11, SJR: 0.967, h-index: 57)
Addictive Behaviors     Hybrid Journal   (Followers: 15, SJR: 1.514, h-index: 92)
Addictive Behaviors Reports     Open Access   (Followers: 5)
Additive Manufacturing     Hybrid Journal   (Followers: 7, SJR: 1.039, h-index: 5)
Additives for Polymers     Full-text available via subscription   (Followers: 20)
Advanced Drug Delivery Reviews     Hybrid Journal   (Followers: 120, SJR: 5.2, h-index: 222)
Advanced Engineering Informatics     Hybrid Journal   (Followers: 11, SJR: 1.265, h-index: 53)
Advanced Powder Technology     Hybrid Journal   (Followers: 16, SJR: 0.739, h-index: 33)
Advances in Accounting     Hybrid Journal   (Followers: 8, SJR: 0.299, h-index: 15)
Advances in Agronomy     Full-text available via subscription   (Followers: 15, SJR: 2.071, h-index: 82)
Advances in Anesthesia     Full-text available via subscription   (Followers: 24, SJR: 0.169, h-index: 4)
Advances in Antiviral Drug Design     Full-text available via subscription   (Followers: 3)
Advances in Applied Mathematics     Full-text available via subscription   (Followers: 6, SJR: 1.054, h-index: 35)
Advances in Applied Mechanics     Full-text available via subscription   (Followers: 10, SJR: 0.801, h-index: 26)
Advances in Applied Microbiology     Full-text available via subscription   (Followers: 21, SJR: 1.286, h-index: 49)
Advances In Atomic, Molecular, and Optical Physics     Full-text available via subscription   (Followers: 16, SJR: 3.31, h-index: 42)
Advances in Biological Regulation     Hybrid Journal   (Followers: 4, SJR: 2.277, h-index: 43)
Advances in Botanical Research     Full-text available via subscription   (Followers: 3, SJR: 0.619, h-index: 48)
Advances in Cancer Research     Full-text available via subscription   (Followers: 26, SJR: 2.215, h-index: 78)
Advances in Carbohydrate Chemistry and Biochemistry     Full-text available via subscription   (Followers: 9, SJR: 0.9, h-index: 30)
Advances in Catalysis     Full-text available via subscription   (Followers: 5, SJR: 2.139, h-index: 42)
Advances in Cellular and Molecular Biology of Membranes and Organelles     Full-text available via subscription   (Followers: 12)
Advances in Chemical Engineering     Full-text available via subscription   (Followers: 24, SJR: 0.183, h-index: 23)
Advances in Child Development and Behavior     Full-text available via subscription   (Followers: 10, SJR: 0.665, h-index: 29)
Advances in Chronic Kidney Disease     Full-text available via subscription   (Followers: 8, SJR: 1.268, h-index: 45)
Advances in Clinical Chemistry     Full-text available via subscription   (Followers: 28, SJR: 0.938, h-index: 33)
Advances in Colloid and Interface Science     Full-text available via subscription   (Followers: 18, SJR: 2.314, h-index: 130)
Advances in Computers     Full-text available via subscription   (Followers: 16, SJR: 0.223, h-index: 22)
Advances in Developmental Biology     Full-text available via subscription   (Followers: 11)
Advances in Digestive Medicine     Open Access   (Followers: 4)
Advances in DNA Sequence-Specific Agents     Full-text available via subscription   (Followers: 5)
Advances in Drug Research     Full-text available via subscription   (Followers: 22)
Advances in Ecological Research     Full-text available via subscription   (Followers: 39, SJR: 3.25, h-index: 43)
Advances in Engineering Software     Hybrid Journal   (Followers: 25, SJR: 0.486, h-index: 10)
Advances in Experimental Biology     Full-text available via subscription   (Followers: 7)
Advances in Experimental Social Psychology     Full-text available via subscription   (Followers: 38, SJR: 5.465, h-index: 64)
Advances in Exploration Geophysics     Full-text available via subscription   (Followers: 3)
Advances in Fluorine Science     Full-text available via subscription   (Followers: 8)
Advances in Food and Nutrition Research     Full-text available via subscription   (Followers: 41, SJR: 0.674, h-index: 38)
Advances in Fuel Cells     Full-text available via subscription   (Followers: 14)
Advances in Genetics     Full-text available via subscription   (Followers: 15, SJR: 2.558, h-index: 54)
Advances in Genome Biology     Full-text available via subscription   (Followers: 11)
Advances in Geophysics     Full-text available via subscription   (Followers: 6, SJR: 2.325, h-index: 20)
Advances in Heat Transfer     Full-text available via subscription   (Followers: 18, SJR: 0.906, h-index: 24)
Advances in Heterocyclic Chemistry     Full-text available via subscription   (Followers: 8, SJR: 0.497, h-index: 31)
Advances in Human Factors/Ergonomics     Full-text available via subscription   (Followers: 22)
Advances in Imaging and Electron Physics     Full-text available via subscription   (Followers: 2, SJR: 0.396, h-index: 27)
Advances in Immunology     Full-text available via subscription   (Followers: 33, SJR: 4.152, h-index: 85)
Advances in Inorganic Chemistry     Full-text available via subscription   (Followers: 9, SJR: 1.132, h-index: 42)
Advances in Insect Physiology     Full-text available via subscription   (Followers: 3, SJR: 1.274, h-index: 27)
Advances in Integrative Medicine     Hybrid Journal   (Followers: 4)
Advances in Intl. Accounting     Full-text available via subscription   (Followers: 4)
Advances in Life Course Research     Hybrid Journal   (Followers: 7, SJR: 0.764, h-index: 15)
Advances in Lipobiology     Full-text available via subscription   (Followers: 1)
Advances in Magnetic and Optical Resonance     Full-text available via subscription   (Followers: 8)
Advances in Marine Biology     Full-text available via subscription   (Followers: 16, SJR: 1.645, h-index: 45)
Advances in Mathematics     Full-text available via subscription   (Followers: 10, SJR: 3.261, h-index: 65)
Advances in Medical Sciences     Hybrid Journal   (Followers: 5, SJR: 0.489, h-index: 25)
Advances in Medicinal Chemistry     Full-text available via subscription   (Followers: 5)
Advances in Microbial Physiology     Full-text available via subscription   (Followers: 4, SJR: 1.44, h-index: 51)
Advances in Molecular and Cell Biology     Full-text available via subscription   (Followers: 21)
Advances in Molecular and Cellular Endocrinology     Full-text available via subscription   (Followers: 10)
Advances in Molecular Toxicology     Full-text available via subscription   (Followers: 6, SJR: 0.324, h-index: 8)
Advances in Nanoporous Materials     Full-text available via subscription   (Followers: 3)
Advances in Oncobiology     Full-text available via subscription   (Followers: 3)
Advances in Organometallic Chemistry     Full-text available via subscription   (Followers: 15, SJR: 2.885, h-index: 45)
Advances in Parallel Computing     Full-text available via subscription   (Followers: 7, SJR: 0.148, h-index: 11)
Advances in Parasitology     Full-text available via subscription   (Followers: 7, SJR: 2.37, h-index: 73)
Advances in Pediatrics     Full-text available via subscription   (Followers: 20, SJR: 0.4, h-index: 28)
Advances in Pharmaceutical Sciences     Full-text available via subscription   (Followers: 14)
Advances in Pharmacology     Full-text available via subscription   (Followers: 13, SJR: 1.718, h-index: 58)
Advances in Physical Organic Chemistry     Full-text available via subscription   (Followers: 7, SJR: 0.384, h-index: 26)
Advances in Phytomedicine     Full-text available via subscription  
Advances in Planar Lipid Bilayers and Liposomes     Full-text available via subscription   (Followers: 3, SJR: 0.248, h-index: 11)
Advances in Plant Biochemistry and Molecular Biology     Full-text available via subscription   (Followers: 8)
Advances in Plant Pathology     Full-text available via subscription   (Followers: 5)
Advances in Porous Media     Full-text available via subscription   (Followers: 4)
Advances in Protein Chemistry     Full-text available via subscription   (Followers: 18)
Advances in Protein Chemistry and Structural Biology     Full-text available via subscription   (Followers: 17, SJR: 1.5, h-index: 62)
Advances in Psychology     Full-text available via subscription   (Followers: 56)
Advances in Quantum Chemistry     Full-text available via subscription   (Followers: 5, SJR: 0.478, h-index: 32)
Advances in Radiation Oncology     Open Access  
Advances in Small Animal Medicine and Surgery     Hybrid Journal   (Followers: 1, SJR: 0.1, h-index: 2)
Advances in Space Research     Full-text available via subscription   (Followers: 332, SJR: 0.606, h-index: 65)
Advances in Structural Biology     Full-text available via subscription   (Followers: 7)
Advances in Surgery     Full-text available via subscription   (Followers: 6, SJR: 0.823, h-index: 27)
Advances in the Study of Behavior     Full-text available via subscription   (Followers: 28, SJR: 1.321, h-index: 56)
Advances in Veterinary Medicine     Full-text available via subscription   (Followers: 14)
Advances in Veterinary Science and Comparative Medicine     Full-text available via subscription   (Followers: 12)
Advances in Virus Research     Full-text available via subscription   (Followers: 5, SJR: 1.878, h-index: 68)
Advances in Water Resources     Hybrid Journal   (Followers: 42, SJR: 2.408, h-index: 94)
Aeolian Research     Hybrid Journal   (Followers: 5, SJR: 0.973, h-index: 22)
Aerospace Science and Technology     Hybrid Journal   (Followers: 304, SJR: 0.816, h-index: 49)
AEU - Intl. J. of Electronics and Communications     Hybrid Journal   (Followers: 8, SJR: 0.318, h-index: 36)
African J. of Emergency Medicine     Open Access   (Followers: 4, SJR: 0.344, h-index: 6)
Ageing Research Reviews     Hybrid Journal   (Followers: 7, SJR: 3.289, h-index: 78)
Aggression and Violent Behavior     Hybrid Journal   (Followers: 390, SJR: 1.385, h-index: 72)
Agri Gene     Hybrid Journal  
Agricultural and Forest Meteorology     Hybrid Journal   (Followers: 15, SJR: 2.18, h-index: 116)
Agricultural Systems     Hybrid Journal   (Followers: 29, SJR: 1.275, h-index: 74)
Agricultural Water Management     Hybrid Journal   (Followers: 36, SJR: 1.546, h-index: 79)
Agriculture and Agricultural Science Procedia     Open Access  
Agriculture and Natural Resources     Open Access   (Followers: 1)
Agriculture, Ecosystems & Environment     Hybrid Journal   (Followers: 48, SJR: 1.879, h-index: 120)
Ain Shams Engineering J.     Open Access   (Followers: 5, SJR: 0.434, h-index: 14)
Air Medical J.     Hybrid Journal   (Followers: 3, SJR: 0.234, h-index: 18)
AKCE Intl. J. of Graphs and Combinatorics     Open Access   (SJR: 0.285, h-index: 3)
Alcohol     Hybrid Journal   (Followers: 9, SJR: 0.922, h-index: 66)
Alcoholism and Drug Addiction     Open Access   (Followers: 5)
Alergologia Polska : Polish J. of Allergology     Full-text available via subscription   (Followers: 1)
Alexandria Engineering J.     Open Access   (Followers: 1, SJR: 0.436, h-index: 12)
Alexandria J. of Medicine     Open Access  
Algal Research     Partially Free   (Followers: 7, SJR: 2.05, h-index: 20)
Alkaloids: Chemical and Biological Perspectives     Full-text available via subscription   (Followers: 3)
Allergologia et Immunopathologia     Full-text available via subscription   (Followers: 1, SJR: 0.46, h-index: 29)
Allergology Intl.     Open Access   (Followers: 5, SJR: 0.776, h-index: 35)
ALTER - European J. of Disability Research / Revue Européenne de Recherche sur le Handicap     Full-text available via subscription   (Followers: 6, SJR: 0.158, h-index: 9)
Alzheimer's & Dementia     Hybrid Journal   (Followers: 45, SJR: 4.289, h-index: 64)
Alzheimer's & Dementia: Diagnosis, Assessment & Disease Monitoring     Open Access   (Followers: 5)
Alzheimer's & Dementia: Translational Research & Clinical Interventions     Open Access   (Followers: 3)
American Heart J.     Hybrid Journal   (Followers: 45, SJR: 3.157, h-index: 153)
American J. of Cardiology     Hybrid Journal   (Followers: 47, SJR: 2.063, h-index: 186)
American J. of Emergency Medicine     Hybrid Journal   (Followers: 34, SJR: 0.574, h-index: 65)
American J. of Geriatric Pharmacotherapy     Full-text available via subscription   (Followers: 6, SJR: 1.091, h-index: 45)
American J. of Geriatric Psychiatry     Hybrid Journal   (Followers: 14, SJR: 1.653, h-index: 93)
American J. of Human Genetics     Hybrid Journal   (Followers: 32, SJR: 8.769, h-index: 256)
American J. of Infection Control     Hybrid Journal   (Followers: 25, SJR: 1.259, h-index: 81)
American J. of Kidney Diseases     Hybrid Journal   (Followers: 31, SJR: 2.313, h-index: 172)
American J. of Medicine     Hybrid Journal   (Followers: 48, SJR: 2.023, h-index: 189)
American J. of Medicine Supplements     Full-text available via subscription   (Followers: 3)
American J. of Obstetrics and Gynecology     Hybrid Journal   (Followers: 174, SJR: 2.255, h-index: 171)
American J. of Ophthalmology     Hybrid Journal   (Followers: 51, SJR: 2.803, h-index: 148)
American J. of Ophthalmology Case Reports     Open Access   (Followers: 2)
American J. of Orthodontics and Dentofacial Orthopedics     Full-text available via subscription   (Followers: 6, SJR: 1.249, h-index: 88)
American J. of Otolaryngology     Hybrid Journal   (Followers: 22, SJR: 0.59, h-index: 45)
American J. of Pathology     Hybrid Journal   (Followers: 23, SJR: 2.653, h-index: 228)
American J. of Preventive Medicine     Hybrid Journal   (Followers: 21, SJR: 2.764, h-index: 154)
American J. of Surgery     Hybrid Journal   (Followers: 32, SJR: 1.286, h-index: 125)
American J. of the Medical Sciences     Hybrid Journal   (Followers: 13, SJR: 0.653, h-index: 70)
Ampersand : An Intl. J. of General and Applied Linguistics     Open Access   (Followers: 5)
Anaerobe     Hybrid Journal   (Followers: 4, SJR: 1.066, h-index: 51)
Anaesthesia & Intensive Care Medicine     Full-text available via subscription   (Followers: 52, SJR: 0.124, h-index: 9)
Anaesthesia Critical Care & Pain Medicine     Full-text available via subscription   (Followers: 3)
Anales de Cirugia Vascular     Full-text available via subscription  
Anales de Pediatría     Full-text available via subscription   (Followers: 2, SJR: 0.209, h-index: 27)
Anales de Pediatría (English Edition)     Full-text available via subscription  
Anales de Pediatría Continuada     Full-text available via subscription   (SJR: 0.104, h-index: 3)
Analytic Methods in Accident Research     Hybrid Journal   (Followers: 2, SJR: 2.577, h-index: 7)
Analytica Chimica Acta     Hybrid Journal   (Followers: 38, SJR: 1.548, h-index: 152)
Analytical Biochemistry     Hybrid Journal   (Followers: 154, SJR: 0.725, h-index: 154)
Analytical Chemistry Research     Open Access   (Followers: 7, SJR: 0.18, h-index: 2)
Analytical Spectroscopy Library     Full-text available via subscription   (Followers: 10)
Anesthésie & Réanimation     Full-text available via subscription  
Anesthesiology Clinics     Full-text available via subscription   (Followers: 21, SJR: 0.421, h-index: 40)
Angiología     Full-text available via subscription   (SJR: 0.124, h-index: 9)
Angiologia e Cirurgia Vascular     Open Access  
Animal Behaviour     Hybrid Journal   (Followers: 143, SJR: 1.907, h-index: 126)
Animal Feed Science and Technology     Hybrid Journal   (Followers: 5, SJR: 1.151, h-index: 83)
Animal Reproduction Science     Hybrid Journal   (Followers: 5, SJR: 0.711, h-index: 78)
Annales d'Endocrinologie     Full-text available via subscription   (SJR: 0.394, h-index: 30)
Annales d'Urologie     Full-text available via subscription  
Annales de Cardiologie et d'Angéiologie     Full-text available via subscription   (SJR: 0.177, h-index: 13)
Annales de Chirurgie de la Main et du Membre Supérieur     Full-text available via subscription  
Annales de Chirurgie Plastique Esthétique     Full-text available via subscription   (Followers: 2, SJR: 0.354, h-index: 22)
Annales de Chirurgie Vasculaire     Full-text available via subscription   (Followers: 1)

        1 2 3 4 5 6 7 8 | Last   [Sort by number of followers]   [Restore default list]

Journal Cover Advances in Quantum Chemistry
  [SJR: 0.478]   [H-I: 32]   [5 followers]  Follow
    
   Full-text available via subscription Subscription journal  (Not entitled to full-text)
   ISSN (Print) 0065-3276
   Published by Elsevier Homepage  [3030 journals]
  • Mean-Field Methods for Time-Dependent Quantum Dynamics of Many-Atom
           Systems
    • Authors: Barak Hirshberg; R. Benny Gerber
      Abstract: Publication date: Available online 7 March 2017
      Source:Advances in Quantum Chemistry
      Author(s): Barak Hirshberg, R. Benny Gerber
      Methods that can accurately describe the quantum dynamics of large molecular systems have many potential applications. Since numerical solution of the time-dependent Schrödinger equation is only possible for systems with very few atoms, approximate methods are essential. This paper describes the development of such methods for this challenging time-dependent many-body quantum mechanical problem. Specifically, we focus on the development of mean-field theories, to which Mark Ratner has contributed greatly over the years, such as the time-dependent self-consistent field method, mixed quantum–classical methods, and the classical separable potentials method. The advantages and limitations of the different variants of mean-field theories are highlighted. Recent developments, aimed at applying mean-field methods for large systems, and their applications are presented. Issues where further methodological advancement is desirable are discussed. Examining the tools available so far, and the recent progress, we conclude there are promising perspectives for future development of mean-field theories for quantum dynamics with applications to realistic systems in important chemical and physical processes.

      PubDate: 2017-03-09T01:32:40Z
      DOI: 10.1016/bs.aiq.2017.01.002
       
  • Electron–Ion Impact Energy Transfer in Nanoplasmas of Coulomb
           Exploding Clusters
    • Authors: Isidore Last; Joshua Jortner
      Abstract: Publication date: Available online 24 February 2017
      Source:Advances in Quantum Chemistry
      Author(s): Isidore Last, Joshua Jortner
      Novel features of analysis and control of nanoplasma dynamics are manifested in elemental and molecular clusters irradiated by a near-infrared intense ultraintense laser pulse, where the laser energy pumped to the nanoplasma electrons is transferred to the cluster ions by Coulomb explosion (CE) and by electron–ion impact mechanisms. The contribution of the electron–ion impact was studied by a microscopic model, together with molecular dynamics simulations of the electron–ion kinetic energy transfer in the course of the electron–ion collision events. The simulations were performed for ionic (He+)N, (Ne+)N, and (Ne4+)N clusters containing weakly charged ions, as well as for (H+)N and (He2+)N clusters consisting of bare nuclei and electrons. The clusters were subjected to femtosecond (τ =30fs) laser pulses with peak intensities of I M =1015–1017 Wcm−2. The force F imp, generated by the electron impact kinetic energy transfer was found to decrease strongly with the exploding cluster radius R, i.e., F imp ∝ R − η , with η ~4–6. The electron impact energy transferred to the periphery ions of clusters (in the size domain of N =104–106) made up less than 2.5% of the maximal ion energy. The laser energy transfer to the nanoplasma involves the dominating contribution of the Coulomb energy and a minor contribution of the electron impact, with the cluster expansion and decay being governed by the CE mechanism.

      PubDate: 2017-03-03T01:11:21Z
      DOI: 10.1016/bs.aiq.2017.01.003
       
  • A Time-Dependent Density Functional Theory Study of the Impact of Ligand
           Passivation on the Plasmonic Behavior of Ag Nanoclusters
    • Authors: Adam P. Ashwell; Mark A. Ratner; George C. Schatz
      Abstract: Publication date: Available online 15 February 2017
      Source:Advances in Quantum Chemistry
      Author(s): Adam P. Ashwell, Mark A. Ratner, George C. Schatz
      We present a detailed study of the impact of ligand passivation on the electronic structures and optical properties of plasmonic Ag nanoclusters using density functional theory (DFT) and time-dependent density functional theory (TD-DFT). The clusters studied are A g 13 5 + , A g 25 S H 18 − , A g 25 N H 2 18 − , A g 32 14 + , and A g 44 S H 30 4 − . We find that the highest occupied ligand orbitals from S (3p) and N (2p) appear just above the conduction band, and this leads to significant ligand-to-metal charge transfer transitions at high energies. Dielectric screening associated with ligand passivation results in reduced HOMO–LUMO gaps and in an increased gap between the HOMO and the valence band associated with the Ag 4d orbitals. Ligand field effects result in splitting of plasmonic peaks, leading to reduced mixing between nearby single-particle excitations. The magnitude of these effects is found to decrease when thiolate ligands are replaced with amine ligands. We also find that, in the case of the A g 44 S H 30 4 − cluster, the ligands localize plasmonic excitations into the core of the cluster.

      PubDate: 2017-02-17T00:46:10Z
      DOI: 10.1016/bs.aiq.2017.01.001
       
  • Series Page
    • Abstract: Publication date: 2017
      Source:Advances in Quantum Chemistry, Volume 74


      PubDate: 2017-02-17T00:46:10Z
       
  • Ab Initio Complex Potential Energy Surfaces From Standard Quantum
           Chemistry Packages
    • Authors: Arie Landau; Debarati Bhattacharya; Idan Haritan; Anael Ben-Asher; Nimrod Moiseyev
      Abstract: Publication date: Available online 7 December 2016
      Source:Advances in Quantum Chemistry
      Author(s): Arie Landau, Debarati Bhattacharya, Idan Haritan, Anael Ben-Asher, Nimrod Moiseyev
      Situations in which a molecule in a given configuration is electronically bound while in another configuration is autoionized are widespread in nature. In these situations, the change in molecular configuration due to nuclear dynamics is the reason the molecule emits free electrons to the surrounding, ie, autoionizes. Such a situation may even happen to molecules in their ground electronic state, for example, it can happen to H 2 − : at some bond lengths, the molecule is autoionized, at some bond lengths its ground state is bound, and at sufficiently large internuclear distances a stable hydrogen atom and a stable negative charged hydrogen, H−, in their ground electronic states, are obtained. In addition, such situations can be seen in electronic scattering from molecules and in cold molecular collisions. For example, in a collision between electronically excited helium atom and a hydrogen molecule in its ground state, metastable complex He*–H2 is formed. As time passes this complex decays to helium in its ground state, H 2 + , and a free electron. In all these cases the molecular dynamics play a key role as the molecules are autoionized. This poses a problem, since the Born–Oppenheimer (BO) approximation is applicable only when the decay process due to ionization is ignored. Therefore, in order to study molecular dynamics and take autoionization into consideration, one should calculate the potential energy surfaces (PES) by imposing outgoing boundary conditions (OBCs) on the electronic wavefunctions. Doing so, the electronic molecular spectrum will be discrete (no continuum), where the PES will be either real (bound electronic states) or complex (metastable molecules that ionize). These complex potential energy surfaces (CPES) are what enables one to take into consideration the electronic autoionization in the molecular dynamics. Nevertheless, calculating CPES by standard quantum chemistry packages (SQCPs) is not a trivial task, since they were designed to calculate bound electronic excited states. Bound states lie on the real plane, unlike metastable states (resonances); therefore, explicit calculation of resonances requires modification of SQCPs. Several different possibilities for calculating CPES by modifying SQCPs are discussed in this review. Yet, the holy grail is to be able to use SQCPs, which are highly efficient codes, for calculating resonances without changing the codes. The main focus of this review will be on new methods, we have developed, that enable calculating CPESs from SQCPs, ie, without any modifications of standard codes. Such methods allow the calculations of polyatomic CPESs, as indicated by our preliminary results.

      PubDate: 2016-12-13T21:45:33Z
      DOI: 10.1016/bs.aiq.2016.10.001
       
  • Cognition of Learning and Memory: What Have Löwdin's Orthogonalizations
           Got to Do With That?
    • Authors: Vipin Srivastava; Suchitra Sampath
      Abstract: Publication date: Available online 5 October 2016
      Source:Advances in Quantum Chemistry
      Author(s): Vipin Srivastava, Suchitra Sampath
      We present some initial results to show that Löwdin's two orthogonalization schemes, namely Symmetric and Canonical, can help us to understand certain important aspects of the brain's competence to learn and memorize. We propose that these orthogonalizations may constitute the physiological actions that the brain may perform to deal with certain types of memories.

      PubDate: 2016-10-12T02:35:41Z
      DOI: 10.1016/bs.aiq.2016.08.001
       
  • Time-Dependent Perturbation Theory with Application to Atomic Systems
    • Authors: Ingvar Lindgren
      Abstract: Publication date: Available online 12 September 2016
      Source:Advances in Quantum Chemistry
      Author(s): Ingvar Lindgren
      A new form of time-dependent perturbation theory has been developed based upon the covariant-evolution operator (CEO), previously introduced by us. This has made it possible to combine time-dependent perturbations, like the quantum-electrodynamical (QED) perturbations, with time-independent interactions, like the Coulomb interaction (electron correlation) in a single perturbation expansion. For the first time quantum-electrodynamical perturbations can then be combined with electron correlation beyond second order. The experimental accuracy is in many cases so high that these effects have become significant. A numerical scheme has been developed where first-order QED effects are combined with the electron correlation and applied to highly charged helium-like ions. This scheme contains the dominating part of the higher-order QED effects and has been applied to highly charged helium-like ions, for which effects beyond second order (two-photon effects) have for the first time been evaluated. The calculations have been performed using Feynman as well as Coulomb gauge. In evaluating effects beyond second order involving radiative QED it was necessary to employ the Coulomb gauge.

      PubDate: 2016-09-17T17:56:17Z
      DOI: 10.1016/bs.aiq.2016.06.002
       
  • State-Quantum-Chemistry Set in a Photonic Framework
    • Authors: Orlando Tapia
      Abstract: Publication date: Available online 30 August 2016
      Source:Advances in Quantum Chemistry
      Author(s): Orlando Tapia
      The photonic scheme provides an abstract perspective to describing chemical and physical processes; it is well adapted for biologically sustained processes too. The scheme is used to help analyze semiclassic pictures in order for a deeper understanding of natural processes to arise. A q-state is not an object (eg, a molecule) but convoluted with a photon field, it hangs somehow on sensitive surfaces revealing an image constructed from q-events: these q-events are joint q-energy and angular momentum bridging probe-to-probing systems. Exchanges between physical states and probing ones establish a reality for a q-state. Thus, in the photonic scheme, a q-state may emerge as an image if appropriately recorded via q-events. Initially collected q-events seem to indicate a random process. However, after gathering these q-events in sufficient numbers, as in a two-slit example, a supportive image develops corresponding more and more to what is known as an interference pattern. Moreover, the unlocking of a spin-triplet state is used to illustrate applications: for instance, the opening required a path starting from a parent spin-singlet excited electronic state. A low-frequency multiphoton mechanism regulated by conservation laws permits the description of a triplet state activation. Of course, the materiality sustaining a q-state must transfer information that is richer than that a classical particle impact would convey. The use we make of quantum mechanics is basically the same that everyone does though without current interpretations; inclusion of photon fields makes the difference by providing quantum mechanisms to accomplish measurements.

      PubDate: 2016-09-03T09:19:15Z
      DOI: 10.1016/bs.aiq.2016.07.001
       
  • High-Resolution Quantum-Mechanical Signal Processing for in vivo NMR
           Spectroscopy
    • Authors: Karen
      Abstract: Publication date: Available online 25 August 2016
      Source:Advances in Quantum Chemistry
      Author(s): Dževad Belkić, Karen Belkić
      High-resolution quantitative signal analysis using the fast Padé transform (FPT) is applied to a specific problem (cerebral asphyxia) within magnetic resonance spectroscopy (MRS) for in vivo pediatric neurodiagnostics. Potential broader implications for the presented methodology are indicated for interdisciplinary research, including quantum chemistry. An iterative averaging procedure is introduced and validated, which could be automatically built-in, to provide denoised spectra, so vitally needed in clinical MRS. The full equivalence of nonparametrically and parametrically generated total shape spectra in the FPT is demonstrated. With subsequent parametric analysis, exceedingly dense component spectra are reliably reconstructed, both with the mixture of absorption and dispersion components (“usual” mode) and by setting the reconstructed phases to zero, in order to eliminate interference effects (“ersatz” mode). Via the ersatz components, the consequences and extent of the said interference effect are distinctly visualized for every overlap of closely located resonances or hidden resonances. Practical implementation of Padé-optimized MRS from in vivo encoded time signals in the clinical setting is hereby demonstrated.

      PubDate: 2016-08-29T06:28:11Z
       
  • Quantum Chemistry and Superconductors
    • Authors: Sven Larsson
      Abstract: Publication date: Available online 3 August 2016
      Source:Advances in Quantum Chemistry
      Author(s): Sven Larsson
      Thirty years after the discovery of high temperature (HT) superconductivity (SC), no by all accepted theory exists. The Bardeen, Cooper, Schrieffer (BCS) model, hewed into the Bloch theory for metals, is unfit for local systems such as cuprates and organic superconductors. In this chapter, we will use a theory that dates back to Landau and Pekar, but we will avoid the effective mass approach by using a total free energy model, as designed for electron transfer problems by Marcus and Jortner. A diffusion equation is used to derive the resistivity in the local case. The original definition of Hubbard U by Mott as a metal-to-metal (or molecule-to-molecule) charge transfer energy will be updated by including the neglected negative terms. It will be shown that the absorption at 2eV in the cuprates is indeed due to Cu–Cu charge transfer, identical to the Hubbard U or Mott transition. The model accounts for bond-length fluctuations due to occupancy of d-orbitals (extended over the ligands), or in the molecular case the π orbitals, and this makes it necessary to make a distinction between adiabatic and vertical Hubbard U. U vert =1.5–3eV while U ad may be a few hundred times smaller. Organic SC in aromatic hydrocarbons will be shortly reviewed and found consistent with the general model. Finally, we will discuss SC in tungsten bronzes discovered in 1964 by Matthias.

      PubDate: 2016-08-04T21:49:07Z
      DOI: 10.1016/bs.aiq.2016.06.005
       
  • Quantum Chemistry with Thermodynamic Condition. A Journey into the
           Supercritical Region and Approaching the Critical Point
    • Authors: Marcelo Hidalgo Cardenuto; Kaline Coutinho; Sylvio Canuto
      Abstract: Publication date: Available online 26 July 2016
      Source:Advances in Quantum Chemistry
      Author(s): Marcelo Hidalgo Cardenuto, Kaline Coutinho, Sylvio Canuto
      Combining Statistical Mechanics and Quantum Chemistry it is possible to study solvent effects in spectroscopy and understand chemical reactivity in solution. However, once the thermodynamic condition can be incorporated, it is possible to advance in other important regions of the phase diagram. Hence supercritical fluids with temperature and pressure beyond the critical point can be studied. Supercritical fluids are of interest both for their remarkable physical chemical properties and the industrial interests. The critical point, however, is apparently not a thermodynamic condition amenable to quantum chemical calculations. This is because it is characterized by intense fluctuations and density inhomogeneity. The correlation length becomes infinite at the critical point. But for points close enough to the critical point the fluctuations disappear, and it is possible to get very close to this rather interesting point in the phase diagram. In this work we review some results for the spectroscopy of molecular systems in the supercritical region and the static dipole polarizability and the refractive index of Ar only 2K above the critical point. The refractive index presents some peculiarities, but it is well behaved as we pass at the critical point. The numerical value obtained of 1.083 is in very good agreement with the experimental value of 1.086. We contend that the proximity of the critical point is amenable to theoretical quantum mechanical studies possibly accessing new physical phenomena.

      PubDate: 2016-08-04T21:49:07Z
      DOI: 10.1016/bs.aiq.2016.06.006
       
  • High-Temperature Superconductivity in Strongly Correlated Electronic
           Systems
    • Authors: Lawrence J. Dunne; Erkki J. Brändas; Hazel Cox
      Abstract: Publication date: Available online 25 July 2016
      Source:Advances in Quantum Chemistry
      Author(s): Lawrence J. Dunne, Erkki J. Brändas, Hazel Cox
      In this chapter we give a selective review of our work on the role of electron correlation in the theory of high-temperature superconductivity (HTSC). The question of how electronic repulsions might give rise to off-diagonal long-range order (ODLRO) in high-temperature superconductors is currently one of the key questions in the theory of condensed matter. This chapter argues that the key to understanding the occurrence of HTSC in cuprates is to be found in the Bohm–Pines Hamiltonian, modified to include a polarizable dielectric background. The approach uses reduced electronic density matrices and discusses how these can be used to understand whether ODLRO giving rise to superconductivity might arise from a Bohm–Pines-type potential which is comprised of a weak long-range attractive tail and a much stronger short-range repulsive Coulomb interaction. This allows time-reversed electron pairs to undergo a superconducting condensation on alternant cuprate lattices. Thus, a detailed summary is given of the arguments that such interacting electrons can cooperate to produce a superconducting state in which time-reversed pairs of electrons effectively avoid the repulsive hard-core of the interelectronic Coulomb interaction but reside on average in the attractive well of the effective potential. In a superconductor the plasma wave function becomes the longitudinal component of a massive photon by the Anderson–Higgs mechanism. The alternant cuprate lattice structure is the key to achieving HTSC in cuprates with d x 2 − y 2 symmetry condensate symmetry.

      PubDate: 2016-08-04T21:49:07Z
      DOI: 10.1016/bs.aiq.2016.06.003
       
  • Quantum Partitioning Methods for Few-Atom and Many-Atom Dynamics
    • Authors: David A. Micha
      Abstract: Publication date: Available online 1 July 2016
      Source:Advances in Quantum Chemistry
      Author(s): David A. Micha
      The subject of this contribution is how projection operators can be constructed to treat a variety of time-dependent phenomena involving interacting molecules, and to treat the dissipative dynamics of a localized subsystem in a large environment. It develops partitioning methods in a functional space of wavefunctions introduced to construct molecular effective potentials and long-lived states from distortion, adiabatic, and fast motion states. It also gives a treatment starting from the statistical density operator, for partitioning in a many-atom system undergoing dissipative dynamics, and shows how to construct contracted density operators with selected total system states, or reduced density operators for localized phenomena in a primary region. The presentation displays related mathematical procedures useful for partitioning of both wavefunctions and density operators and for derivation of their equations of motion.

      PubDate: 2016-08-04T21:49:07Z
      DOI: 10.1016/bs.aiq.2016.06.001
       
  • Electron Propagator Theory: Foundations and Predictions
    • Authors: Héctor H. Corzo; J.V. Ortiz
      Abstract: Publication date: Available online 1 July 2016
      Source:Advances in Quantum Chemistry
      Author(s): Héctor H. Corzo, J.V. Ortiz
      Electron propagator theory is an efficient means to accurately calculating electron binding energies and associated Dyson orbitals that is systematically improvable and easily interpreted in terms of familiar concepts of valence theory. After a brief discussion of the physical meaning of the poles and residues of the electron propagator, the Dyson quasiparticle equation is derived. Practical approximations of the self-energy operator in common use are defined in terms of the elements of the Hermitian superoperator Hamiltonian matrix. Methods that retain select self-energy terms in all orders of the fluctuation potential include the two-particle-one-hole Tamm–Dancoff approximation, the renormalized third-order method, the third-order algebraic diagrammatic construction, and the renormalized, nondiagonal second-order approximation. Methods based on diagonal second-order and third-order elements of the self-energy matrix, such as the diagonal second-order, diagonal third-order, outer valence Green's function, partial third-order, and renormalized partial third-order approximations, provide efficient alternatives. Recent numerical tests on valence, vertical ionization energies of representative, small molecules, and a comparison of arithmetic and memory requirements provide guidance to users of electron propagator software. A survey of recent applications and extensions illustrates the versatility and interpretive power of electron propagator methodology.

      PubDate: 2016-08-04T21:49:07Z
      DOI: 10.1016/bs.aiq.2016.05.001
       
  • Vibrational Quantum Squeezing Induced by Inelastic Collisions
    • Authors: Berrondo
      Abstract: Publication date: Available online 25 June 2016
      Source:Advances in Quantum Chemistry
      Author(s): M. Berrondo, J. Récamier
      The energy transfer between vibrational and translational degrees of freedom during an inelastic collision between two molecules induces quantum squeezing in the vibrational molecular coordinate under very diverse circumstances. In this chapter, we present the relevant calculation for the very simple case of an atom–diatomic collinear transition, the Landau–Teller model. Both the uncertainty of the vibrational coordinate and the Husimi function show clear evidence of quantum squeezing. Our model treats the relative translation of the colliding species as a classical variable. The vibrational motion of the diatomic molecule is treated quantum mechanically in terms of the evolution operator and coherent states. The corresponding classical and quantum equations of motion are coupled. We first consider the squeezing of a coherent vibrational state where we include the dynamic evolution of the Husimi function. The second case corresponds to an initial thermal distribution of vibrational states where we plot the position uncertainty for the squeezed vibrational state.

      PubDate: 2016-08-04T21:49:07Z
       
  • Per-Olov Löwdin
    • Authors: Jan Linderberg; Yngve Erkki John Sabin
      Abstract: Publication date: Available online 14 June 2016
      Source:Advances in Quantum Chemistry
      Author(s): Jan Linderberg, Yngve Öhrn, Erkki J. Brändas, John R. Sabin


      PubDate: 2016-06-16T18:01:38Z
       
  • Specifics on the Scientific Legacy of Per-Olov Löwdin
    • Authors: Carlos F. Bunge
      Abstract: Publication date: Available online 8 June 2016
      Source:Advances in Quantum Chemistry
      Author(s): Carlos F. Bunge
      Per-Olov Löwdin was an inspiring and compelling teacher. His most prominent papers were written more than 50 years ago, whereas since then quantum chemistry, its software, and its computers have changed almost beyond recognition. In accurate calculations with truncation energy errors, an important part of Per-Olov’s themes and thoughts appears highly relevant today in applications to atoms and small molecules. My purpose here is to place projection operators, natural orbitals, error bounds, and the variational theorem for finite Hermitian matrices, in the light of current challenges in the field.

      PubDate: 2016-06-16T18:01:38Z
      DOI: 10.1016/bs.aiq.2016.04.004
       
  • From Numerical Orbitals to Analytical Ones and Back
    • Authors: Jan Linderberg
      Abstract: Publication date: Available online 2 June 2016
      Source:Advances in Quantum Chemistry
      Author(s): Jan Linderberg
      Attempting to survey and review some developments in the design and use of atomic basis sets for molecular electronic structure calculations from the perspective of Per-Olov Löwdin's contributions this chapter is offered as a contribution to the celebration of the centennial of his birth.

      PubDate: 2016-06-16T18:01:38Z
      DOI: 10.1016/bs.aiq.2016.04.003
       
  • The Time-Dependent Variational Principal in Quantum Mechanics and Its
           Application
    • Authors: Yngve
      Abstract: Publication date: Available online 31 May 2016
      Source:Advances in Quantum Chemistry
      Author(s): Yngve Öhrn
      This account of the time-dependent variational principle is presented in memory of Per-Olov Löwdin on the occasion of the centenary of his birth. The material presented here has been published as part of a book chapter, 1 and is reintroduced here in recognition of Löwdin's interest in this topic. 2 Also the importance of the use of coherent state parameters as functions of time is emphasized, as well as the connection to the electron nuclear dynamics (END) theory. 3

      PubDate: 2016-06-16T18:01:38Z
       
  • Resonances in the Continuum, Field-Induced Nonstationary States, and the
           State- and Property-Specific Treatment of the Many-Electron Problem
    • Authors: Cleanthes A. Nicolaides
      Abstract: Publication date: Available online 30 April 2016
      Source:Advances in Quantum Chemistry
      Author(s): Cleanthes A. Nicolaides
      I start by thanking Erkki Brändas and Jack Sabin for inviting me to contribute to this special volume commemorating the 100th birthday of Per-Olov Löwdin. Their initiative adds to previous ones involving conferences and books that have been dedicated to him, all expressing the respect and admiration that Löwdin inspired throughout his scientific career in his associates and professional colleagues. Although there are many people who are better qualified to comment on Löwdin's personality and achievements, I take this opportunity to state briefly my impressions of him. I met Löwdin only a few times during the 1970s and 1980s, in conferences and in Sanibel symposia, starting with the conference on “The Future of Quantum Chemistry” that was held in Dalseter, Norway, Sept. 1–5, 1976, organized by J.-L. Calais and O. Goscinski to celebrate his 60th birthday. Those encounters (which included a couple of cocktail parties and soccer games where he played goalie) led to a nice rapport, even though I was much younger. They were sufficient to leave me with the best of impressions about his openness, about his interest in assisting young scientists from all over the world, and about his scientific inquisitiveness and aim for mathematical clarity and justification. Löwdin's scientific and organizational achievements were instrumental in advancing the cause of quantum chemistry in Sweden as well as internationally, especially during the 1950s and 1960s. For example, the Uppsala summer schools and the Sanibel winter symposia became institutions. He is remembered with respect and affection not only for his research papers but also for his exceptional activity which accelerated the recognition of quantum chemistry as a distinct scientific discipline with a diverse community of theoretical scientists. As a member of this community, I feel lucky for the opportunity given to me by the Editors to contribute the paper which follows. The paper summarizes elements of theories and computational methods that we have constructed and applied over the years for the nonperturbative solution of many-electron problems (MEPs), in the absence or presence of strong external fields, concerning resonance/nonstationary states with a variety of electronic structures. Using brief arguments and comments, I explain how these MEPs are solvable in terms of practical time-independent or time-dependent methods, which are based on single- or multistate Hermitian or non-Hermitian formulations. The latter result from the complex eigenvalue Schrödinger equation (CESE) theory. The CESE has been derived, for field free as well as for field-induced resonances, by starting from Fano's 1961 discrete-continuum standing-wave superposition, and by imposing outgoing-wave boundary conditions on the resulting solution. Regularization is effected via the use of complex coordinates for the orbitals of the outgoing electron(s) in each channel. The Hamiltonian coordinates remain real. The computational framework emphasizes the use of appropriate forms of the trial wavefunctions and the choice of function spaces according to the state- and property-specific methodology, using either nonrelativistic or relativistic Hamiltonians. In most cases, the bound part of excited wavefunctions is obtained via state-specific “HF or MCHF plus selected parts of electron correlation” schemes. This approach was first introduced to the theory of multiply excited and inner-hole autoionizing states in 1972, and its feasibility was demonstrated even in cases of multiply excited negative-ion scattering resonances. For problems of states interacting with strong and/or ultrashort pulses, the many-electron time-dependent Schrödinger equation is solved via the state-specific expansion approach. Applications have produced a plethora of numerical data that either compare favorably with measurements or constitute testable predictions of properties of N-electron field-free and field-induced nonstationary states.

      PubDate: 2016-05-19T18:20:39Z
      DOI: 10.1016/bs.aiq.2016.03.001
       
  • Series Page
    • Abstract: Publication date: 2016
      Source:Advances in Quantum Chemistry, Volume 73


      PubDate: 2016-02-09T10:00:56Z
       
  • Series Page
    • Abstract: Publication date: 2016
      Source:Advances in Quantum Chemistry, Volume 72


      PubDate: 2016-01-22T01:13:25Z
       
  • A Sturmian Approach to Photoionization of Molecules
    • Authors: Carlos Mario Granados-Castro; Lorenzo Ugo Ancarani; Gustavo Gasaneo; Dario M. Mitnik
      Pages: 3 - 57
      Abstract: Publication date: Available online 6 January 2016
      Source:Advances in Quantum Chemistry
      Author(s): Carlos Mario Granados-Castro, Lorenzo Ugo Ancarani, Gustavo Gasaneo, Dario M. Mitnik
      An accurate theoretical description of photoionization processes is necessary in order to understand a wide variety of physical and chemical phenomena and allows one to test correlation effects of the target. Compared to the case of many-electron atoms several extra challenges occur for molecules. The scattering problem is generally multicenter and highly noncentral. The molecular orientation with respect to the polarization of the radiation field must also be taken into account. These features make the computational task much more cumbersome and expensive than for atomic targets. In order to calculate cross sections, one needs to describe the ejected electron with a continuum wavefunction with appropriate Coulomb asymptotic conditions. Making a number of initial approximations, many different theoretical/numerical methods have been proposed over the years. However, depending on the complexity of the molecule, agreement among them is not uniform and many features of the experimental data are not so well reproduced. This is illustrated through a number of examples. In order to have a global theoretical overview, we present a survey of most of the methods available in the literature, indicating their application to different molecules. Within a Born–Oppenheimer, one-center expansion and single active electron approximation, we then introduce a Sturmian approach to describe photoionization of molecular targets. The method is based on the use of generalized Sturmian functions for which correct boundary conditions can be chosen. This property makes the method computationally efficient, as illustrated with results for H2O, NH3, and CH4.

      PubDate: 2016-01-09T19:17:40Z
      DOI: 10.1016/bs.aiq.2015.06.002
       
  • Analytic Calculation of Momentum Distribution and Compton Profiles of
           Atoms Using Hartree–Fock–Roothaan Method: Applications to Atoms
           2≤Z≤10
    • Authors: Telhat Ozdogan; Melek Eraslan
      Pages: 173 - 182
      Abstract: Publication date: Available online 8 January 2016
      Source:Advances in Quantum Chemistry
      Author(s): Telhat Ozdogan, Melek Eraslan
      An analytical formula have been presented for momentum density and Compton profiles of atoms using Hartree–Fock–Roothaan method. The obtained formula includes the linear combination coefficients of molecular orbitals, auxiliary functions B mn l (α, β; q) and K n l (α, q), and Gaunt coefficients. Computer programs have been constructed for atomic Compton profiles and including functions. Utilizing these programs, Compton profiles of atoms 2≤ Z ≤10 have been calculated for a wide range of incident photon energy. It is seen that the obtained results for Compton profiles of these atoms are in good agreement with the more recent theoretical and experimental works.

      PubDate: 2016-01-09T19:17:40Z
      DOI: 10.1016/bs.aiq.2015.09.002
       
  • Configuration Interaction Monte Carlo with Coupled Clusters Wave Functions
    • Authors: Alessandro Roggero; Paolo Mori; Abhishek Mukherjee; Francesco Pederiva
      Pages: 315 - 332
      Abstract: Publication date: Available online 8 January 2016
      Source:Advances in Quantum Chemistry
      Author(s): Alessandro Roggero, Paolo Mori, Abishek Mukherjee, Francesco Pederiva
      Quantum Monte Carlo algorithms in Fock space have gained popularity in the last few years. Here we review the Configuration Interaction Monte Carlo (CIMC) algorithm. CIMC provides a way to implement the imaginary time propagation projecting the ground state of a given Hamiltonian in a model Hilbert space that (1) makes use of an importance function, and in particular of the wave function computed in a Coupled Cluster calculation, and (2) exploits a continuous time algorithm to eliminate the approximations due to the use of a finite imaginary time step. Some results and discussions from the implementation in the three-dimensional electron gas and first row atoms are also presented.

      PubDate: 2016-01-09T19:17:40Z
      DOI: 10.1016/bs.aiq.2015.09.003
       
 
 
JournalTOCs
School of Mathematical and Computer Sciences
Heriot-Watt University
Edinburgh, EH14 4AS, UK
Email: journaltocs@hw.ac.uk
Tel: +00 44 (0)131 4513762
Fax: +00 44 (0)131 4513327
 
Home (Search)
Subjects A-Z
Publishers A-Z
Customise
APIs
Your IP address: 54.145.81.105
 
About JournalTOCs
API
Help
News (blog, publications)
JournalTOCs on Twitter   JournalTOCs on Facebook

JournalTOCs © 2009-2016