MOLECULAR-DYNAMICS STUDIES OF LENNARD-JONES LIQUID-MIXTURES .5. LOCAL COMPOSITION IN SEVERAL KINDS OF EQUIMOLAR MIXTURES WITH DIFFERENT COMBINING RULE

Local fractions of two components around each kind of central particle have been calculated for the purpose of obtaining detailed structural information on binary model mixtures from molecular dynamics data for three equimolar mixtures of Lennard-Jones fluids with different combining rules for the energy parameter. It was found that well-defined local fractions can be determined in each case and that they are different from the overall mole fractions in nonideal mixtures. The validity of empirical formulations for local compositions has been tested against the present results and it was suggested that the Boltzmann factor relation between local and overall compositions may be inadequate to describe relative configuration of two components around a central particle. © 1979 American Institute of Physics.