As well as 'EvsLC', a similar functionality is provided as
by 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 'System.Name.DF'. The data can be used to calculate the delta factor proposed in Ref. .