Variational calculation of highly excited rovibrational energy levels of H2O2.

Results are presented for highly accurate ab initio variational calculation of the rotation-vibration energy levels of H2O2 in its electronic ground state. These results use a recently computed potential energy surface and the variational nuclear-motion programs WARV4, which uses an exact kinetic energy operator, and TROVE, which uses a numerical expansion for the kinetic energy. The TROVE calculations are performed for levels with high values of rotational excitation, J up to 35.

Accurate ab initio potential energy surface and vibration-rotation energy levels of hydrogen peroxide.

The accurate ground-state potential energy surface of hydrogen peroxide, H(2)O(2), has been determined from ab initio calculations using the coupled-cluster approach in conjunction with the correlation-consistent basis sets up to septuple-zeta quality. Results obtained with the conventional and explicitly correlated coupled-cluster methods were compared. The core-electron correlation, scalar relativistic, and higher-order valence-electron correlation effects were taken into account.