Using diffusion Monte Carlo to evaluate the initial conditions for classical studies of the photodissociation dynamics of HCl dimer

An approach for evaluating the initial conditions for classical studies of the photodissociation dynamics of molecular clusters is described. This approach is based on an approximate separation of the momentum and coordinate space probability distributions, evaluated using a wave function that is obtained from a Diffusion Monte Carlo simulation. Using the initial conditions that are generated by this approach, the photodissociation dynamics of HCl dimer is studied. Excellent agreement between the calculated and experimental angular momentum and vibrational energy distributions for the remaining HCl molecule and the kinetic energy distribution of the dissociated hydrogen atom are obtained. The kinetic energy distribution for the chlorine atom and angular distributions of the remaining hydrogen and chlorine atoms are also obtained and dynamical information contained in these distributions is discussed.