coefficients of LiCs2PO4 (LCPO) by introducing the partial response functionals on the basis
of first principles calculations. The SHG response of LCPO is dominated by the metal‐cation‐
centered groups CsO6 and LiO4, not by the nonmetal‐cation‐centered groups PO4
expected from the existing models and theories. The SHG coefficients of LCPO are
determined mainly by the occupied orbitals O 2p and Cs 5p as well as by the unoccupied …