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Assessing the role of H artree‐ F ock exchange, correlation energy and long range corrections in evaluating ionization potential, and electron affinity in density functional theory
Author(s) -
Vikramaditya Talapunur,
Lin ShiangTai
Publication year - 2017
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.24828
Subject(s) - electron affinity (data page) , ionization energy , hybrid functional , density functional theory , ionization , perturbation theory (quantum mechanics) , electronic correlation , range (aeronautics) , hartree–fock method , work (physics) , chemistry , electron , correlation , statistical physics , computational chemistry , atomic physics , physics , molecule , materials science , quantum mechanics , mathematics , ion , geometry , composite material
Accurate determination of ionization potentials (IPs), electron affinities (EAs), fundamental gaps (FGs), and HOMO, LUMO energy levels of organic molecules play an important role in modeling and predicting the efficiencies of organic photovoltaics, OLEDs etc. In this work, we investigate the effects of Hartree Fock (HF) Exchange, correlation energy, and long range corrections in predicting IP and EA in Hybrid Functionals. We observe increase in percentage of HF exchange results in increase of IPs and decrease in EAs. Contrary to the general expectations inclusion of both HF exchange and correlation energy (from the second order perturbation theory MP2) leads to poor prediction. Range separated Hybrid Functionals are found to be more reliable among various DFT Functionals investigated. DFT Functionals predict accurate IPs whereas post HF methods predict accurate EAs. © 2017 Wiley Periodicals, Inc.