Quantum study of the bending relaxation of H2O by collision with H

ABSTRACT Vibrationally excited levels of the H2O molecule are currently detected in various environments interstellar medium (ISM), and collisional data for H2O, including vibration with main colliders ISM, needed. The present study focuses on bending relaxation by collision H when taking bending–rotation coupling explicitly into account rigid-bender close-coupling (RB-CC) method. With this aim, a new four-dimensional potential energy surface mode is developed from large grid ab initio energies computed using high level theory. For purely rotational transitions, our RB-CC rates show very good agreement rigid-rotor calculations performed (PES) those available literature. Calculations pure transitions inside ?2 = 1 compared their equivalents 0. Vibrational quenching also calculated found to be much more efficient through rather than He.