Different self-consistent field SCF iteration schemes for open-shell systems are discussed. After a brief summary of the well-known level shifting and Ε½ . damping procedure, we describe the quadratically convergent SCF QCSCF approach based on the gradient and the Hessian matrix in a space of orbital
Spin-restricted open-shell self-consistent-field theory
β Scribed by Ernest R. Davidson
- Publisher
- Elsevier Science
- Year
- 1973
- Tongue
- English
- Weight
- 210 KB
- Volume
- 21
- Category
- Article
- ISSN
- 0009-2614
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β¦ Synopsis
A method is given for eliminating the off-diagonal lqrangian multipliers which appear in open-shell SCF theory. This lcads to a set of coupled eigenvalue equations which is easily solved for a new guess to the SCF orbit&. This proccdurc has proven more conveient than many others now in use.
π SIMILAR VOLUMES
The quadratically convergent approach.to solving the correct SW equations for generai open-sheIL systems (with orthogonal orbitals..'i,e., multiconfiguration-SCF or Hattree-Fock} is derived and used to discuss other less complicated a Hz0 ZIAl [(lal)2 (2a# (lbl)2 (lJ~2) 8 proaches. Representative ca
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