First-principles simulation of supercooled liquid alloys.

Accurate simulation of multicomponent alloys demands a first-principles approach because empirical potentials become increasingly inaccurate and difficult to develop with each additional constituent element. In contrast, the computational difficulty of simulating an alloy from first principles remains essentially independent of the number of elements. However, equilibration times increase with the number of elements, regardless of the choice of interaction, owing to the need for longer-range diffusion to adequately sample configuration space. The difficulty is exacerbated at low temperatures because of the rapid decline of diffusion constants. Here we discuss the application of replica exchange molecular dynamics to aid equilibration of supercooled alloys, and we also mention the possibility of Hamiltonian exchange molecular dynamics to accelerate equilibration at high temperatures.