OPAL: A multiscale multicenter simulation package based on MPI-2 protocol

By using MPI-2 standard, we designed and implemented a new multiscale simulation architecture OPAL. It requires minimum modification to existing simulation code as maintaining the execution efficiency. The new architecture is capable of dynamical region identification, dynamical process spawning, and is grid-computing friendly. We demonstrated its usage and power with a simple test case: NaCl dissociation in water. The code shows excellent linear scaling capability, and no obvious degradation is observed. The communication time used by OPAL is negligible compared with its execution time, proving its high efficiency.