Calculation of positron binding energies using the generalized any particle propagator theory

Autor(es)

Romero, Jonathan ^[1] ; Charry, Jorge A. ^[1] ; Flores-Moreno, Roberto ^[2] ; Varella, Marcio T. do N. ^[3] ; Reyes, Andres ^{[3, 1]}

Afiliação do(s) autor(es)

^[1] Univ Nacl Colombia, Dept Chem, Bogota - Colombia

^[2] Univ Guadalajara, Dept Quim, Guadalajara Jal 44430 - Mexico

^[3] Univ Sao Paulo, Inst Fis, BR-05315970 Sao Paulo - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Journal of Chemical Physics; v. 141, n. 11 SEP 21 2014.
• Citações Web of Science: 15

Resumo

We recently extended the electron propagator theory to any type of quantum species based in the framework of the Any-Particle Molecular Orbital (APMO) approach {[}J. Romero, E. Posada, R. Flores-Moreno, and A. Reyes, J. Chem. Phys. 137, 074105 (2012)]. The generalized any particle molecular orbital propagator theory (APMO/PT) was implemented in its quasiparticle second order version in the LOWDIN code and was applied to calculate nuclear quantum effects in electron binding energies and proton binding energies in molecular systems {[}M. Diaz-Tinoco, J. Romero, J. V. Ortiz, A. Reyes, and R. Flores-Moreno, J. Chem. Phys. 138, 194108 (2013)]. In this work, we present the derivation of third order quasiparticle APMO/PT methods and we apply them to calculate positron binding energies (PBEs) of atoms and molecules. We calculated the PBEs of anions and some diatomic molecules using the second order, third order, and renormalized third order quasiparticle APMO/PT approaches and compared our results with those previously calculated employing configuration interaction (CI), explicitly correlated and quantum Montecarlo methodologies. We found that renormalized APMO/PT methods can achieve accuracies of similar to 0.35 eV for anionic systems, compared to Full-CI results, and provide a quantitative description of positron binding to anionic and highly polar species. Third order APMO/PT approaches display considerable potential to study positron binding to large molecules because of the fifth power scaling with respect to the number of basis sets. In this regard, we present additional PBE calculations of some small polar organic molecules, amino acids and DNA nucleobases. We complement our numerical assessment with formal and numerical analyses of the treatment of electron-positron correlation within the quasiparticle propagator approach. (C) 2014 AIP Publishing LLC. (AU)

• Processo FAPESP: 13/07712-6 - Afinidades positrônicas de moléculas poliatômicas: implementação de gaussianas explicitamente correlacionadas no método Any Particle Molecular Orbital
• Beneficiário: Márcio Teixeira do Nascimento Varella
• Modalidade de apoio: Auxílio à Pesquisa - Pesquisador Visitante - Internacional