Hydrodynamic properties of the perfect hard-sphere crystal: microscopic computations with Helfand moments

Within the framework of the local equilibrium approach, the equilibrium and nonequilibrium properties relevant to the hydrodynamics of the perfect hard-sphere crystal were obtained through molecular dynamics simulations using the Helfand moments associated with momentum and energy transport. Because this crystal is face-centered cubic, the hydrodynamic properties we considered were hydrostatic pressure, isothermal bulk modulus, specific heat capacities and their ratio, three isothermal elastic constants <?CDATA (C₁₁T,C₁₂T,C₄₄T)?> ( C 11 T , C 12 T , C 44 T ) , heat conductivity, and three viscosities <?CDATA (η₁₁,η₁₂,η₄₄)?> ( η 11 , η 12 , η 44 ) (in Voigt’s notation). These properties were computed as a function of the particle density. The pressure and transport coefficients diverge near the close-packing density, as the collision frequency per particle also diverges.