title: Anharmonicity of weakly bound Li(+)-(H2)n (n = 1-3) complexes.
abstract: The anharmonicity of Li(+)-(H(2))(n) (n = 1, 2, and 3) complexes is studied using the vibrational self-consistent field (VSCF) approach. The H-H stretching frequency shifts of Li(+)-(H(2))(n) complexes are calculated with the coupled-cluster method including all single and double excitations with perturbative triples (CCSD(T)) level of theory with the cc-pVTZ basis set. The calculated IR active H-H stretching frequency in Li(+)-H(2), Li(+)-(H(2))(2) and Li(+)-(H(2))(3) is red-shifted by 121, 109, and 96-99 cm(-1), respectively, relative to that of isolated H(2). The calculated red shifts and their trends are in good agreement with the available experimental data.
authors.affiliation: Department of Chemistry, Iowa State University, Ames, Iowa 50011, USA.
authors.forename: Nuwan
authors.initials: N
authors.lastname: De Silva
authors.forename: Bosiljka
authors.initials: B
authors.lastname: Njegic
authors.forename: Mark S
authors.initials: MS
authors.lastname: Gordon