| Autor: |
Edward F. Valeev, Liguo Kong |
| Rok vydání: |
2011 |
| Předmět: |
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| Zdroj: |
The Journal of chemical physics. 135(21) |
| ISSN: |
1089-7690 |
| Popis: |
The [2]R12 method [M. Torheyden and E. F. Valeev, J. Chem. Phys. 131, 171103 (2009)10.1063/1.3254836] is an explicitly correlated perturbative correction that can greatly reduce the basis set error of an arbitrary electronic structure method for which the two-electron density matrix is available. Here we present a spin-adapted variant (denoted as SF-[2]R12) that is formulated completely in terms of spin-free quantities. A spin-free cumulant decomposition and multi-reference generalized Brillouin condition are used to avoid three-particle reduced density matrix completely. The computational complexity of SF-[2]R12 is proportional to the sixth power of the system size and is comparable to the cost of the single-reference MP2-R12 method. The SF-[2]R12 method is shown to decrease greatly the basis set error of multi-configurational wave functions. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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