Get FE3 NI S4 = b51 = nickel/iron/sulfur cluster Get FE3 NI S4 = wcc = fe(3)-ni(1)-s(4) cluster; c cluster cubane Get FE4 NI S4 = xcc = fe(4)-ni(1)-s(4) cluster; c cluster Get FE4 NI S5 = nfs = fe(4)-ni(1)-s(5) cluster
