Path Integral Monte Carlo for Fictitious Identical Particles with ξ-Ensemble

Abstract

In this work, a path integral Monte Carlo (PIMC) algorithm for fictitious identical particles (FIP) is proposed by introducing a $\xi$-ensemble and performing PIMC simulations on the resulting $\xi$-ensemble partition function. The PIMC algorithm with the $\xi$-ensemble allows us to obtain the thermodynamic properties of FIP for different $\xi$ values in a single simulation. Moreover, it also accelerates the simulation by improving the sampling efficiency, compared to the usual case where independent simulations are performed for each $\xi$ value, in the sense that the autocorrelation time of samples belonging to the same $\xi$ sector is decreased. Simulations of the uniform electron gas and uniform warm dense beryllium are performed to validate the improved algorithm and study the improvement in its sampling efficiency.

arXiv comment20 pages, 9 figures