Explicit and implicit multi‐center integrations |
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Authors: | Wolfhard H. G. Koch |
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Affiliation: | Facultad de Estudios Superiores Zaragoza, Universidad Nacional, Autónoma de México, Av. Guelatao 66, Col. Ejercito de Oriente, Del. Iztapalapa, México D.F. 09230, Mexico |
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Abstract: | We present truncated expansions of multicenter one‐electron nuclear attraction and two‐electron repulsion integrals over localized basis functions in terms of one‐ and two‐center integrals of “Coulomb,” “exchange,” and “hybrid” type. Two variants are discussed: the “Explicit Multi‐center Integrations” and the “Implicit Multi‐Center Integrations” (abbreviated as “EMCI” and “IMCI”, respectively). While EMCI also deals with individual integrals, the IMCI option is the more appealing one: it enables us to evaluate the entire matrix elements of “Restricted Hartree–Fock”‐type in a very effective and chemically meaningful way. Due to the diatomic nature of our expansions, integrations over “Slater‐Type Orbitals” become well‐feasible, too. © 2012 Wiley Periodicals, Inc. |
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Keywords: | multicenter attraction and repulsion integrals Diatomic Integral Expansions Restricted Fock‐matrix elements Slater‐Type Orbital sets |
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