A Rigid Bender Study of the Bending Relaxation of H2O and D2O by Collisions with Ar

The bending relaxation of H2O and D2O by collisions with Ar is studied at the Close Coupling level. Two new 4D PES are developed for these two systems. They are tested by performing rigid rotor calculations as well as by computing the D2O−Ar bound states. The results are compared with available theoretical and experimental data. Propensity rules for the dynamics are discussed and compared to those of H2O colliding with Ne or He. The bending relaxation cross sections and rates are then calculated for these two systems. The results are analysed and compared with available experimental data. A comparison is made between the Ar‐H2O and Ar‐D2O systems. The comparison includes the calculation of two 4D‐PESs and the rigid bender calculation of the vibrational quenching cross section as well as the analysis of the dynamics propensity rules.