Adiabatic pseudospectral calculation of vibrational states of four atom molecules: Application to hydrogen peroxide

We use our adiabatic pseudospectral method (APS) to calculate energy levels of the H2O2 molecule up to 5000 cm−1. Reasonably high accuracy (a few wave numbers) is achieved for a fully six dimensional calculation in a few hours of CPU time on an IBM 580 workstation. This contrasts with previous calculations on the same system which required 50–100 times more computational effort for a similar level of accuracy. The method presented here is both general and robust, and will allow routine studies of six dimensional potential surfaces and the associated spectroscopy, while making calculations on still larger systems feasible.