A compound comprising a composition Ax(M′1−aM″a)y(XD4)z, Ax(M′1−aM″a)y(DXD4)z, or Ax(M′1−aM″a)y(X2D7)z, (A1−aM″a)xM′y(XD4)z, (A1−aM″a)xM′y(DXD4)z, or (A1−aM″a)xM′y(X2D7)z. In the compound, A is at least one of an alkali metal and hydrogen, M′ is a first-row transition metal, X is at least one of phosphorus, sulfur, arsenic, molybdenum, and tungsten, M″ any of a Group IIA, IIIA, IVA, VA, VIA, VIIA, VIIIA, IB, IIB, IIIB, IVB, VB, and VIB metal, D is at least one of oxygen, nitrogen, carbon, or a halogen, 0.0001