# async

An optional keyword to perform an asynchronous parallel focusing Poisson-Boltzmann equation. The syntax is

    async {rank}

where `rank` is the integer ID of the particular processor to masquerade as. Processor IDs range from 0 to N-1, where N is the total number of processors in the run (see pdime). Processor IDs are related to their position in the overall grid by \(p = nx ny k + nx j + i\) where \(nx\) is the number of processors in the x-direction, \(ny\) is the number of processors in the y-direction, \(nz\) is the number of processors in the z-direction, \(i\) is the index of the processor in the x-direction, \(j\) is the index of the processor in the y-direction, \(k\) is the index of the processor in the z-direction, and \(p\) is the overall rank of the processor.