Vitenskapelig artikkel   2008

Dahle, Pål; Helgaker, T; Jonsson, Dan Johan; Taylor, PR

Publikasjonsdetaljer

Tidsskrift:

Physical Chemistry, Chemical Physics - PCCP, vol. 10, p. 3377–3382–6, 2008

Utgiver:

Royal Society of Chemistry (RSC) Publishing

Utgave:

23

Internasjonale standardnumre:

Trykt: 1463-9076
Elektronisk: 1463-9084

Lenker:

FULLTEKST: http://publications.nr.no/4903/Dahle_-_Second-order_Moller-Plesset_calculations_on_the_wa.pdf
DOI: doi.org/10.1039/b803577f

The Gaussian-type orbital and Gaussian-type geminal (GGn) model is applied to the water molecule, at the level of second-order Møller–Plesset (MP2) theory. In GGn theory, correlation factors are attached to all doubly-occupied orbital pairs (GG0), to all doubly-occupied and singly-excited pairs (GG1), or to all orbital pairs (GG2). Optimizing the GG2 model using a weak-orthogonality functional, we obtain the current best estimate of the all-electron MP2 correlation energy of water, −361.95 mEh. In agreement with previous observations, the GG1 model performs almost as well as the GG2 model (−361.26 mEh), whereas the GG0 model is poorer (−351.36 mEh). For the barrier to linearity of water, we obtain an MP2 correlation contribution of −463 ± 5 cm−1.