Verification check of atom energy for contributing and non-contributing atoms v000

Determines whether the per-atom energy of non-contributing atoms is zero, and if the total energy is equal to the sum of per-atom energies, based on a face-centered cubic (fcc) structure. A single mixed configuration is generated with all supported species randomly distributed. Atoms are defined as either contributing, where they contribute to the total system energy, or non-contributing, in which the per-atom energy should be zero.