Dissipative dynamics in many‐atom systems: A density matrix treatment

Abstract

Abstract The dynamics of a many‐atom system are described in terms of the density operator solution of the Liouville–von Neumann equation, for either isolated or dissipative (open) conditions. The treatment introduces a partial Wigner transform of the density operator of the isolated system or of a primary region of interest, respectively, classifying degrees of freedom as quantal or quasi‐classical. A secondary region (the medium) is treated as a stochastic environment leading to a dissipative dynamics of the primary region. Dissipative phenomena are described in terms of dissipative potentials and rate operators. The quantum and quasi‐classical degrees of freedom can be identified with the electronic and nuclear variables of a many‐atom system to provide a description of electronic rearrangement and excitations during dissipative phenomena. © 2002 Wiley Periodicals, Inc. Int J Quantum Chem, 2002