On the density matrix approach of intramolecular relaxation processes.

In this paper we derive the generalized master equations for the S(1) system coupled with the S(2) system, with the S(1) and S(2) systems embedded in a heat bath. This formalism can be applied to a number of problems like vibrational redistribution, dynamic effect of vibrational relaxation on electronic relaxation in condensed media, etc. In this paper the importance of the memory function associated with a relaxation process is emphasized.