This paper, the second part of a series, extended the capabilities of the LADERA FORTRAN code for massively parallel dual control volume grand canonical molecular dynamics (DCV-GCMD). DCV-GCMD was a hybrid of two more common molecular simulation techniques (grand canonical Monte Carlo and molecular dynamics) which allowed the direct molecular-level modelling of diffusion under a chemical potential gradient. The present version of the code, LADERA-B had the capability of modelling systems with explicit intramolecular interactions such as bonds, angles, and dihedral rotations. The utility of the code for studying gradient-driven diffusion of small molecules through polymers was demonstrated by applying it to two model systems. LADERA-B included another feature, which was the use of neighbour lists in force calculations. This feature increased the speed of the code but presented several challenges in the parallel hybrid algorithm. There was discussion on how these problems were addressed and how this implementation results in a significant increase in speed over the original LADERA. Scaling results were presented for LADERA-B on two massively parallel message-passing machines. An algorithm to enable the implementation of dual control volume grand canonical molecular dynamics (DCV-GCMD) on massively parallel (MP) architectures was presented. DCV-GCMD could be thought of as hybridization of molecular dynamics and grand canonical Monte Carlo (GCMC) and was developed to make possible the simulation of gradient-driven diffusion. The method had broad application to such problems as membrane separations, drug delivery systems, diffusion in polymers and zeolites, etc. The massively parallel algorithm for the DCV-GCMD method was implemented in a code named LADERA which employs the short range Lennard-Jones potential for pure fluids and multi-component mixtures including bulk and confined (single pore as well as amorphous solid materials) systems. Like DCV-GCMD, LADERA's MP algorithm could be thought of as a hybridization of two different algorithms, spatial molecular dynamics and spatial GCMC. The DCV-GCMD method was described fully followed by the DCV-GCMD parallel algorithm employed in LADERA. The scaling characteristics of the MP algorithm were presented together with the results of the application of LADERA to ternary and quaternary Lennard-Jones mixtures.

Massively Parallel Dual Control Volume Grand Canonical Molecular Dynamics with LADERA II. Gradient Driven Diffusion through Polymers. Ford, D.M., Heffelfinger, G.S.: Molecular Physics, 1998, 94[4], 673-83