Discontinuous molecular dynamics for rigid bodies: Applications

Event-driven molecular dynamics simulations are carried out on two rigid-body systems which differ in the symmetry of their molecular mass distributions. First, simulations of methane in which the molecules interact via discontinuous potentials are compared with simulations in which the molecules interact through standard continuous Lennard-Jones potentials. It is shown that under similar conditions of temperature and pressure, the rigid discontinuous molecular dynamics method reproduces the essential dynamical and structural features found in continuous-potential simulations at both gas and liquid densities. Moreover, the discontinuous molecular dynamics approach is demonstrated to be between 3 and 100 times more efficient than the standard molecular dynamics method depending on the specific conditions of the simulation. The rigid discontinuous molecular dynamics method is also applied to a discontinuous-potential model of a liquid composed of rigid benzene molecules, and equilibrium and dynamical properties are shown to be in qualitative agreement with more detailed continuous-potential models of benzene. The few qualitative differences in the angular dynamics of the two models are related to the relatively crude treatment of variations in the discontinuous repulsive interactions as one benzene molecule rotates by another. (c) 2007 American Institute of Physics.PT: J; CR: ALDER BJ, 1959, J CHEM PHYS, V31, P459 BELLEMANS A, 1980, MOL PHYS, V39, P781 CACELLI I, 2004, J AM CHEM SOC, V126, P14278 CHAPELA GA, 1984, MOL PHYS, V53, P139 CHAPELA GA, 1989, CHEM PHYS, V129, P201 DELAPENA LH, 2007, J CHEM PHYS, V126 DEMICHELE C, 2006, J PHYS CHEM B, V110, P8064 DING F, 2003, PROTEINS, V53, P220 DUANE S, 1987, PHYS LETT B, V195, P216 DULLWEBER A, 1997, J CHEM PHYS, V107, P5840 FALCONE DR, 1967, J PHYS CHEM-US, V71, P2754 MACKERELL AD, 1998, J PHYS CHEM B, V102, P3586 NGUYEN HD, 2006, J AM CHEM SOC, V128, P1890 PRESS WH, 1992, NUMERICLA RECIPES FO RAPAPORT DC, 1979, J CHEM PHYS, V71, P3299 RAPAPORT DC, 2004, ART MOL DYNAMICS SIM VANZON R, CONDMAT0612404 VANZON R, IN PRESS J COMPUT PH ZACHAROPOULOS N, 2005, J CHEM PHYS, V122 ZHOU YQ, 1999, J MOL BIOL, V293, P917; NR: 20; TC: 0; J9: J CHEM PHYS; PG: 12; GA: 138VLSource type: Electronic(1