Forward-backward semiclassical dynamics for systems of indistinguishable particles

Forward-backward semiclassical dynamics (FBSD) in conjunction with an accurate path integral (PI) description of the density operator provides an accurate, yet practical methodology for simulating important quantum mechanical effects in the dynamics of many-particle systems. In this paper we extend the FBSD methodology to systems of indistinguishable bosons or fermions. Test applications on model systems solvable by numerically exact basis set methods demonstrate that FBSD allows accurate descriptions of the dynamics in fluids characterized by quantum statistics. Specifically, the PI-FBSD methodology successfully captures the frequency shift and spectral narrowing associated with Bose-Einstein condensation. The methodology is also applied to a Lennard-Jones fluid of identical bosons.