Ca 2 La(MS 4 )(BS 3 ) (M = Ge/Si and Sn/Si): high-performance infrared nonlinear optical materials designed using an atomic site co-occupancy strategy

Ca 2 La(Ge 0.72 Si 0.28 S 4 )(BS 3 ) and Ca 2 La(Sn 0.75 Si 0.25 S 4 )(BS 3 ) are designed by mixing Ge 4+ or Sn 4+ into the Si 4+ site and they achieve obviously enhanced SHG effects.