Molecular dynamics sim, binaries for MPICH parallelization

 GROMACS is a versatile package to perform molecular dynamics, i.e. simulate
 the Newtonian equations of motion for systems with hundreds to millions of
 particles.
 .
 It is primarily designed for biochemical molecules like proteins and lipids
 that have a lot of complicated bonded interactions, but since GROMACS is
 extremely fast at calculating the nonbonded interactions (that usually
 dominate simulations) many groups are also using it for research on non-
 biological systems, e.g. polymers.
 .
 This package contains only the core simulation engine with parallel
 support using the MPICH (v3) interface. It is suitable for nodes of a
 processing cluster, or for multiprocessor machines.