Parallel Fourier Path-Integral Monte Carlo calculations of absolute free energies and chemical equilibria Original Research Article

We present a parallel implementation of the Fourier Path Integral Monte Carlo method for calculating the absolute free energies of many-body systems. The implementation adopts the message-passing paradigm for parallelization, with the use of the Message Passing Interface (MPI) libraries. A portable computer program, written using Fortran 90, has been developed and tested on a variety of platforms such as the SGI Origin, the IBM SP, and the Cray T3D and T3E. We have used the program to demonstrate the efficacy of importance sampling in configuration space. We have also used the program to calculate the partition function, and hence the absolute free energies, of triatomic molecules and four-body systems.