Building transition probabilities for any condition using scaled cumulative energy transfer functions in H2O H2O collisions

RAÚL A. BUSTOS-MARÚN; , EDUARDO A. CORONADO; JUAN. C. FERRERO

Orleans, Francia

Simposio; 19th International Symposium on Gas Kinetics; 2006

Universidad de Orleans, francia

 The energy transfer process between  highly vibrationally excited H₂O in a gas bath of H₂O in thermal equilibrium at different internal energies and temperatures  has been studied by  classical trajectory calculations (1) using the ab initio  PJT2 and VRT(MCY)  intra and intermolecular potentials respectively(2,3).   As in  previous work, the results are  analyzed using a cumulative probability distribution  Q(DE) of the amount of energy transfered obtained by direct count of the number of trajectories that transfer an amount of energy equal or greater than a certain amount DE(4). 

The transition porbabilities are  obtained by differentiation of the respective cumulative function. In this work we apply this  treatment for both up and down transitions,  which allow us to apply more rigurous detailed balance contrains. Scaling of Q(DE) in terms of the mean down and up energy transfer transfered for each group of trajectories, results in a unique distribution. This fact and the use of  detailed balance arguments,  allow us to build the whole P(E,E), for any condition by knowing only one parameter i.e. the value of DE _all for a given temperatue and internal energy.