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Linear superposition of optimized non-orthogonal Slater determinants for singlet states

✍ Scribed by Henrik Koch; Esper Dalgaard


Publisher
Elsevier Science
Year
1993
Tongue
English
Weight
616 KB
Volume
212
Category
Article
ISSN
0009-2614

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✦ Synopsis


The implementation of two simple ideas concerning the optimization of a many-electron ground state wavefunction is reported. Firstly, the wavefunction is written as a sum of non-orthogonal Slater determinants. Secondly, the optimization is carried out by adding one determinant at a time and determining the best possible orbitals to be used in that determinant. Technical details of gradient-optimization methods are included. Calculations on the electronic ground state of Be, BH and HZ0 indicate that near full-C1 accuracy can be attained using a comparatively small number of determinants. Finally, it is conjectured that a geminal approach might provide an effective solution to the problem of initiating the optimization sequence for each successively added determinant.