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Convergence enhancement in the iterative solution of the second‐order contracted Schrödinger equation
Author(s) -
Alcoba D. R.,
Casquero F. J.,
Tel L. M.,
PérezRomero E.,
Valdemoro C.
Publication year - 2005
Publication title -
international journal of quantum chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.484
H-Index - 105
eISSN - 1097-461X
pISSN - 0020-7608
DOI - 10.1002/qua.20441
Subject(s) - convergence (economics) , schrödinger equation , matrix (chemical analysis) , iterative method , order (exchange) , energy (signal processing) , mathematics , quantum , chemistry , physics , computational chemistry , quantum mechanics , mathematical analysis , algorithm , finance , chromatography , economics , economic growth
The iterative solution of the contracted Schrödinger equation is coupled with a second‐order reduced density matrix purification procedure, which corrects its N‐ and S‐representability defects, and with a regulating convergence device. An analysis of the effects of these new implementations is reported. The method is applied to the calculation of the potential energy curves of the BeH 2 and Li 2 molecules. The results compare very closely with those of the full configurations interaction. © 2005 Wiley Periodicals, Inc. Int J Quantum Chem, 2005