MASSIVELY-PARALLEL DUAL CONTROL-VOLUME GRAND-CANONICAL MOLECULAR-DYNAMICS WITH LADERA-I - GRADIENT DRIVEN DIFFUSION IN LENNARD-JONES FLUIDS

A new algorithm to enable the implementation of dual control volume gr and canonical molecular dynamics (DCV-GCMD) on massively parallel (MP) architectures is presented. DCV-GCMD can be thought of as hybridizati on of molecular dynamics (MD) and grand canonical Monte Carlo (GCMC) a nd was developed recently to make possible the simulation of gradient- driven diffusion. The method has broad application to such problems as membrane separations, drug delivery systems, diffusion in polymers an d zeolites, etc. The massively parallel algorithm for the DCV-GCMD met hod has been implemented in a code named LADERA which employs the shor t range Lennard-Jones potential for pure fluids and multicomponent mix tures including bulk and confined (single pore as well as amorphous so lid materials) systems. Like DCV-GCMD, LADERA's MP algorithm can be th ought of as a hybridization of two different algorithms, spatial MD an d spatial GCMC. The DCV-GCMD method is described fully followed by the DCV-GCMD parallel algorithm employed in LADERA. The scaling character istics of the new MP algorithm are presented together with the results of the application of LADERA to ternary and quaternary Lennard-Jones mixtures.