Selection of domains for coarse and fine levels of description in mixed-potential simulations

An example of a mixed-potential molecular dynamics simulation is presented for amorphous silica. Pair potentials are used in the roles of embedding and embedded regions to allow us to study on-the-fly selection of a region for the more accurate description by embedded potentials. Brittle fracture with fast crack growth is the example that we choose to elucidate the characteristics of an amorphous system that lead to reliable prediction of the location of the initial fracture in the unbiased system. We conclude that a properly chosen wavelet analysis will permit such on-the-fly identification of those regions in a multi-scale simulation whose properties need to be described at the highest available accuracy.