四点水模型是否支持update gpu？ - 计算化学公社

To completely avoid communication for constraints and/or to have the update run on a GPU, the system needs to support so-called “update groups” (or no constraints at all). Update groups are supported when all atoms involved in coupled constraints are coupled directly to one central atom and consecutively ordered, not interdispersed with non-constrained atoms. An example is a compactly described methyl group. For atomistic force fields with constraints = h-bonds this means in practice that in the topology hydrogens come adjacent to their connected heavy atom. In addition, when virtual sites are present, the constructing atoms should all be constrained together and the virtual site and constructing atoms should be consecutive, but the order does not matter. The TIP4P water model is an example of this. Whether or not update groups are used is noted in the log file. When they cannot be used, the reason for disabling them is also noted.