On the Ordering of Orbital Energies in the ROHF Method: Koopmans’ Theorem versus Aufbau Principle Full article
| Source | Quantum Systems in Physics, Chemistry, and Biology : Advances in Concepts and Applications Compilation, Springer. Cham.2017. 449 c. ISBN 978-3-319-50254-0. |
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| Journal |
Progress in Theoretical Chemistry and Physics
ISSN: 1567-7354 |
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| Output data | Year: 2017, Volume: 30, Pages: 17-37 Pages count : 21 DOI: 10.1007/978-3-319-50255-7_2 | ||
| Tags | Atom Mn; Aufbau principle; Endofullerene N @ C60; Koopmans’ theorem; ROHF method | ||
| Authors |
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| Affiliations |
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Funding (2)
| 1 | Federal Agency for Scientific Organizations | 0303-2016-0001 |
| 2 | Russian Foundation for Basic Research | 15-03-00830 |
Abstract:
The restricted open-shell Hartree-Fock (ROHF) method in its different formulations is a standard tool used by quantum chemists for studying open-shell systems. This work presents a discussion of specific difficulties which arise in the
ROHF method in those cases where the orbital energies violate the Aufbau principle (AP). The AP violations are often treated in the literature as a deficiency of both a ROHF method leading to these violations and of the respective computational results. We summarize examples of different AP violations and analyze them from the viewpoint of both Koopmans’ theorem (KT) and experimental ionization potentials. We show that the main source of AP violations is a specific ordering of the ROHF orbital energies based on the orbital occupancies. In those cases, where the orbital energies obey KT, the violations of the AP reflect the physical reality. To overcome computational difficulties which arise in the iterative SCF procedure, we describe a simple and effective orbital-energy scaling technique which enables one
to perform ROHF computations of systems violating the Aufbau principle
Cite:
Plakhutin B.N.
, Novikov A.V.
, Polygalova N.E.
, Prokhorov T.E.
On the Ordering of Orbital Energies in the ROHF Method: Koopmans’ Theorem versus Aufbau Principle
In compilation Quantum Systems in Physics, Chemistry, and Biology : Advances in Concepts and Applications. – Springer., 2017. – C.17-37. – ISBN 978-3-319-50254-0. DOI: 10.1007/978-3-319-50255-7_2 Scopus РИНЦ AN OpenAlex
On the Ordering of Orbital Energies in the ROHF Method: Koopmans’ Theorem versus Aufbau Principle
In compilation Quantum Systems in Physics, Chemistry, and Biology : Advances in Concepts and Applications. – Springer., 2017. – C.17-37. – ISBN 978-3-319-50254-0. DOI: 10.1007/978-3-319-50255-7_2 Scopus РИНЦ AN OpenAlex
Dates:
| Published online: | May 19, 2017 |
Identifiers:
| Scopus: | 2-s2.0-85042788833 |
| Elibrary: | 48670673 |
| Chemical Abstracts: | 2018:1851924 |
| OpenAlex: | W2614241668 |