Path integral formulation of centroid dynamics for systems obeying Bose-Einstein statistics

This paper presents a formal foundation for the recent extension [J. Chem. Phys. 110, 3647 (1999)] of the centroid molecular dynamics (CMD) method to systems obeying Bose-Einstein statistics. It is shown that the introduction of centroid phase space coordinates corresponding to individual physical p articles allows one to obtain (exact) canonical averages within the framewo rk of the bosonic CMD method. It is also shown that formally exact expressi ons for quantum mechanical Kubo transformed correlation functions can be wr itten in terms of individual particle centroids and that a CMD approximatio n can be introduced. Calculations for a bosonic trimer are used as an illus tration of the new concepts introduced in this work. (C) 2001 American Inst itute of Physics.