Get best estimate of minimum cost/mol based on known data

        Args:
            comp:
                Composition as a pymatgen.core.structure.Composition
        Returns:
            float of cost/mol

def get_cost_per_mol(self, comp):
        """
        Get best estimate of minimum cost/mol based on known data

        Args:
            comp:
                Composition as a pymatgen.core.structure.Composition
        Returns:
            float of cost/mol
        """

        comp = comp if isinstance(comp, Composition) else Composition(comp)
        decomp = self.get_lowest_decomposition(comp)
        return sum(k.energy_per_atom * v * comp.num_atoms for k, v in
                   decomp.items())