As well as 'EvsLC', a similar functionality is provided as
MD.Type DFby which OpenMX automatically calculates the total energy of the system with volumes of -6, -4, -2, 0, 2, 4, and 6 %, where the original structure given in the input file is taken to be the reference. The regulation of volume is simply performed by considering uniform change of lattice vectors, a-, b-, and c-axes. The volume and the corresponding total energy are output to a file '*.DF'. The data can be used to calculate the delta factor proposed in Ref. .