PATH-INTEGRAL MONTE-CARLO ENERGY AND STRUCTURE OF THE QUANTUM HARD-SPHERE SYSTEM USING EFFICIENT PROPAGATORS

Path-integral Monte Carlo simulations neglecting exchange and involving different propagators (crude, Barker's, Jacucci-Omerti's, and Cao-Berne's) have been performed to study the quantum hard-sphere system at several state points ranging from the fluid to the solid phase (ρ*=0.7834; 0.1 < λ*B ≤ 0.4). Energies, necklace radii of gyration and quantum pair radial distribution functions (instantaneous, linear response, self-correlation, and necklace center of mass) have been computed and compared where possible with available data. The results indicate remarkably great performances for the efficient propagators as compared with the crude choice. Even though by lowering the temperature the three efficient propagators lead to the formation of a solid phase, quantitative differences between them are significant just from that stage (λ*B ≤ 0.3). © 1995 American Institute of Physics.