Full-dimensional quantum calculation of the vibrational energy levels of hydrogen peroxide (HOOH)

Vibrational levels of HOOH up to 6000 cm(-1) are accurately determined on a newly developed ab initio potential using the Lanczos algorithm. The six-d imensional Hamiltonian is discretized in terms of a direct-product potentia l optimized discrete variable representation (DVR) for the radial coordinat es and a non-direct product finite basis representation (FBR) comprised of uncoupled spherical harmonics for the angular coordinates. The action of th e potential energy operator is calculated on a direct-product grid via a fa ctorized FBR-DVR transformation. All energy levels below 3000 cm(-1) are as signed and compared with existing theoretical and experimental data. (C) 20 00 Elsevier Science B.V. All rights reserved.