where A R is the antisymmetrizer operator which exchanges all the electron spin-spatial coordinates x within the group R, and det | ... | indicates the Slater determinant, Huzinaga and coworkers found out that an optimum {f R i } set which minimize the energy E while holding fixed the {f S i } sets with S 6 = R, and imposing the conditions in eqs. ( ) and ( ), is given by 16-18 : "