Holomorphic Hartree-Fock Theory: The Nature of Two-Electron Problems
Holomorphic Hartree-Fock Theory: The Nature of Two-Electron Problems
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DOI:
10.1021/acs.jctc.7b00980
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发表时间:
2018-02-01
影响因子:
5.5
通讯作者:
Thom, Alex J. W.
中科院分区:
文献类型:
--
作者:
Burton, Hugh G. A.;Gross, Mark;Thom, Alex J. W.
We explore the existence and behavior of holomorphic restricted Hartree-Fock (h-RHF) solutions for two-electron problems. Through algebraic geometry, the exact number of solutions with n basis functions is rigorously identified as 1/2(3 '' - 1), proving that states must exist for all molecular geometries. A detailed study on the h-RHF states of HZ (STO-3G) then demonstrates both the conservation of holomorphic solutions as geometry or atomic charges are varied and the emergence of complex h-RHF solutions at coalescence points. Using catastrophe theory, the nature of these coalescence points is described, highlighting the influence of molecular symmetry. The h-RHF states of HHeH2+ and HHeH (STO-3G) are then compared, illustrating the isomorphism between systems with two electrons and two electron holes. Finally, we explore the h-RHF states of ethene (STO-3G) by considering the pi electrons as a two-electron problem and employ NOCI to identify a crossing of the lowest energy singlet and triplet states at the perpendicular geometry.