Expansion of the unrestricted determinant in the basis of paired orbitals
| Autor: | Sergey Ph. Ruzankin, Igor Zilberberg |
|---|---|
| Rok vydání: | 2004 |
| Předmět: |
Physics
Atomic orbital Basis (linear algebra) Quantum mechanics General Physics and Astronomy Unrestricted Hartree–Fock Computer Science::Computation and Language (Computational Linguistics and Natural Language and Speech Processing) Physical and Theoretical Chemistry Space (mathematics) Linear combination Linear subspace Spin contamination Spin-½ |
| Zdroj: | Chemical Physics Letters. 394:165-170 |
| ISSN: | 0009-2614 |
| DOI: | 10.1016/j.cplett.2004.06.126 |
| Popis: | An analysis of spin mixture contained in the unrestricted determinant using Lowdin–Amos-Hall paired orbitals (POs) is developed. The space of POs is divided into subspaces of completely, partially and non-overlapping orbitals. Spin contamination is shown to be associated with the ‘active’ space of 2k partially overlapping POs with k being in practice fairly small number. In the basis of POs the unrestricted determinant is expanded in a linear combination of restricted determinants describing ‘basis’ configurations contained 0,1, … ,k pairs of spatially separated α and β spins. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
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