Coulomb Sturmians as a basis for molecular calculations
2012; Taylor & Francis; Volume: 110; Issue: 15-16 Linguagem: Inglês
10.1080/00268976.2012.658876
ISSN1362-3028
Autores Tópico(s)Advanced Physical and Chemical Molecular Interactions
ResumoAbstract Almost all modern quantum chemistry programs use Gaussian basis sets even though Gaussians cannot accurately represent the cusp at atomic nuclei, nor can they represent the slow decay of the wave function at large distances. The reason that Gaussians dominate quantum chemistry today is the great mathematical difficulty of evaluating interelectron repulsion integrals when exponential-type orbitals (ETOs) are used. In this paper we show that when many-centre Coulomb Sturmian ETOs are used as a basis, the most important integrals can be evaluated rapidly and accurately by means of the theory of hyperspherical harmonics. For the remaining many-centre integrals, Coulomb Sturmians are shown to have advantages over other ETOs. Pilot calculations are performed on N-electron molecules using the Generalized Sturmian Method. Keywords: molecular calculationsSturmiansexponential type orbitalsgeneralized Sturmian methodinterelectron repulsion integrals
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