Vibrational relaxation in CO+He collisions: Sensitivity to interaction potential and details of quantum calculations

Abstract

The present work investigates the sensitivity of cross sections for vibrational relaxation in He+CO collisions to details of quantum coupled-states calculations and the choice of vibrational wave functions used for evaluation of the coupling matrix elements. It is illustrated that the J-labeled coupled-states (CS) approach provides results in close agreement with accurate close coupling calculations and experimental measurements while the l-labeled approximation leads to cross sections underestimating the accurate data by a large factor. It is shown that centrifugal distortion of vibrational wave functions enhances cross sections for vibrational relaxation by approximately an energy independent factor. It is found that vibrationally inelastic cross sections are more sensitive to high-order terms in the Legendre expansion of the interaction potential when the J-labeled CS approach and the accurate vibrational wave functions with centrifugal distortion are used for the calculations.