Quantum Monte Carlo study of rovibrational states utilizing rotating wavefunctions: Application to H2O

We applied the procedure developed by Prudente [Chem. Phys. Lett. 302, 249 (1999)] to compute the rovibrational energy levels of the water molecule. T he procedure utilizes rotating wavefunctions as the trial basis in the corr elation-function quantum Monte Carlo method. The procedure originally teste d for a rotating harmonic oscillator and rotating Morse potential, has been extended for triatomic systems, replacing the spherical harmonics by the W igner functions. We computed the rovibrational levels of the water molecule and compared the results with the experiment, and they are shown to be acc urate. (C) 1999 American Institute of Physics. [S0021-9606(99)00238-X].