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Explicitly correlated frequency‐independent second‐order green's function for accurate ionization energies
Author(s) -
Ohnishi Yuya,
Tenno Seiichiro
Publication year - 2016
Publication title -
journal of computational chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.907
H-Index - 188
eISSN - 1096-987X
pISSN - 0192-8651
DOI - 10.1002/jcc.24468
Subject(s) - basis set , ionization , limit (mathematics) , ab initio , ionization energy , function (biology) , basis (linear algebra) , convergence (economics) , physics , order (exchange) , computational chemistry , atomic physics , chemistry , quantum mechanics , density functional theory , ion , mathematics , mathematical analysis , geometry , finance , evolutionary biology , economics , biology , economic growth
Explicitly correlated second‐order Green's function (GF2‐F12) is presented and applied to polycyclic aromatic hydrocarbons (PAHs), oligothiophene, and porphyrins. GF2 suffers from slow convergence of orbital expansions as in the ordinary post Hartree–Fock methods in ab initio theory, albeit the method is capable of providing quantitatively accurate ionization energies (IE) near the complete basis set limit. This feature is significantly mitigated by introducing F12 terms of explicitly correlated electronic structure theory. It is demonstrated that GF2‐F12 presents accurate IE with augmented triple‐zeta quality of basis sets. The errors from experimental results are typically less than 0.15 eV for PAHs. © 2016 Wiley Periodicals, Inc.