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On the test of different atomic exchange functionals
Author(s) -
Santamaria R.,
Kaplan I. G.,
Novaro O.
Publication year - 1995
Publication title -
international journal of quantum chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.484
H-Index - 105
eISSN - 1097-461X
pISSN - 0020-7608
DOI - 10.1002/qua.560560415
Subject(s) - open shell , shell (structure) , variety (cybernetics) , expression (computer science) , energy exchange , energy (signal processing) , exchange interaction , statistical physics , physics , atomic physics , computer science , materials science , quantum mechanics , artificial intelligence , atmospheric sciences , ferromagnetism , composite material , programming language
The yet unknown exchange‐correlation energy functional and the lack of a systematic way to find such a functional has led to propose different expressions for exchange, on the one hand, and correlation on the other, by several authors. A common factor in the design of exchange functionals is to reproduce different kinds of energies rather than the important atomic shell structure. We present a strategy for testing the behavior of exchange functionals based on the reproduction of atomic shell structure. A variety of well‐known exchange functionals are tested on He (closed shell), Li (open shell), and Be (closed subshell). Important differences are found among them. Finally, we propose an exchange energy functional that includes a Becke‐88‐type expression and, in addition, a nongradient correction term that leads to improved shell structure behavior. © 1995 John Wiley & Sons, Inc.