Computation of the transport coefficients of binary mixtures of argon-krypton, krypton-xenon, and argon-xenon by molecular dynamics

A reverse nonequilibrium molecular dynamics method for calculating the mutual diffusion coefficient for binary fluids

“…From Table 2, our mutual diffusion coefficients are consistent with Schoen and Hoheisel's (1984), but differ clearly from Pas and Zwolinski's (1991), for which there are several possible reasons: the difference in system size (108 particles in Pas and Zwolinski as opposed to 6000 in this study); the difference in the cut-off radius, about 0.88 nm as opposed to 1.0 nm; the different time step of integrating the equations of motion (10 fs opposed to 2 fs); and the difference in length of the simulation. Note that the density of 3000Ar/3000Kr at 115.77 K and 101.3 kPa is 1839.3 kg/m 3 which agrees well with that of Schoen and Hoheisel's (1984) 1837.8 kg/m 3 (0.7901), but is smaller than that of Pas and Zwolinski's (1991) 1864.8 kg/m 3 .…”

“…To compare our results with those of previous simulations (Schoen and Hoheisel, 1984;Pas and Zwolinski, 1991), a binary mixture of 3000Ar atoms and 3000Kr atoms in an orthorhombic periodic cell (L x ¼3.23 nm, L y ¼ 3.56 nm, L z ¼29.12 nm) has been studied at 115.77 K and 101.3 kPa. The mutual diffusion coefficient D AB for a binary mixture is a function of temperature, composition, and pressure .…”

“…Thus the thermodynamic factor is included in our EMD calculations. The calculated diffusion coefficients D Ar , D Kr , and D ArKr from our EMD and previous MD results (Schoen and Hoheisel, 1984;Pas and Zwolinski's, 1991) are presented in Table 2. We note that the mutual diffusion coefficients calculated using the center-of-mass mean-square displacement of Ar, D Ar ArKr , are identical to that using the center-of-mass mean-square displacement of Kr, D Kr ArKr , as it should be.…”

“…The details are summarized in Table 1. The Lennard-Jones parameters used for Ar (ε Ar ¼ 0:9961 kJ=mol, σ ar ¼ 0:3405 nm, m Ar ¼ 39:95 g=mol) and Kr (ε Kr ¼ 1:3885 kJ=mol, σ Kr ¼ 0:3670 nm, m Kr ¼ 83:80 g=mol) are from Pas and Zwolinski (1991). The cutoff distance for nonbonded interactions was 1.0 nm.…”

“…MD simulation is a good choice when experiments are impossible, unfeasible or simply too expensive (Cussler, 2009). Many equilibrium MD simulations have been performed to calculate self-and mutual diffusion coefficients for two or three component systems (for example: Jolly and Bearman, 1980;Schoen and Hoheisel, 1984;MacGowan, 1986;Hoheisel and Vogelsang, 1988;Pas and Zwolinski, 1991;van de Ven-lucassen et al, 1999;Min et al, 2007;Liu et al, 2011;Schnell et al, 2011;Pařez et al, 2013). Liu et al (2013) reviewed the methods for predicting mutual diffusion coefficients from MD simulations, recently.…”