caa a22 4500 605487413 CHVBK 20210128100450.0 cr unu---uuuuu 210128e20150701xx s 000 0 eng 10.1007/s00214-015-1682-y doi (NATIONALLICENCE)springer-10.1007/s00214-015-1682-y Mayer I. Research Centre for Natural Sciences, Hungarian Academy of Sciences, P.O.Box 286, 1519, Budapest, Hungary aut Hermitian "chemical” Hamiltonian: an alternative ab initio method [Elektronische Daten] [I. Mayer] Some previous results of the present author are combined in order to develop a Hermitian version of the "Chemical Hamiltonian Approach.” In this framework the second quantized Born-Oppenheimer Hamiltonian is decomposed into one- and two-center components, if some finite basis corrections are omitted. (Nochanges are introduced into the one- and two-center integrals, while projective expansions are used for the three- and four-center ones, which become exact only in the limit of complete basis sets.) The total molecular energy calculated with this Hamiltonian can then presented as a sum of the intraatomic and diatomic energy terms which were introduced in our previous "chemical energy component analysis” scheme. The corresponding modified Hartree-Fock-Roothaan equations are also derived; they do not contain any three- and four-center integrals, while the non-empirical character of the theory is conserved. This scheme may be useful also as a "layer” in approaches like ONIOM. Springer-Verlag Berlin Heidelberg, 2015 Chemical Hamiltonian Approach nationallicence Alternative non-empirical SCF formalism nationallicence Second quantized Hamiltonian nationallicence Excluding three- and four-center integrals nationallicence Projective integral approximation nationallicence Theoretical Chemistry Accounts Springer Berlin Heidelberg 134/7(2015-07-01), 1-10 1432-881X 134:7<1 2015 134 214 https://doi.org/10.1007/s00214-015-1682-y text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s00214-015-1682-y text/html Onlinezugriff via DOI NATIONALLICENCE 100 1- Mayer I. Research Centre for Natural Sciences, Hungarian Academy of Sciences, P.O.Box 286, 1519, Budapest, Hungary aut NATIONALLICENCE 773 0- Theoretical Chemistry Accounts Springer Berlin Heidelberg 134/7(2015-07-01), 1-10 1432-881X 134:7<1 2015 134 214