Parallel Fourier Path-integral Monte Carlo calculations of absolute free energies and chemical equilibria

We present a parallel implementation of the Fourier Path Integral Monte Car lo 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 o n a variety of platforms such as the SGI Origin, the IBM SP. and the Gray T 3D and T3E. We have used the program to demonstrate the efficacy of importa nce sampling in configuration space. We have also used die program to calcu late the partition function. and hence the absolute free energies, of triat omic molecules and four-body systems. (C) 2000 Elsevier Science B.V. All ri ghts reserved.