Theoretical insights into double-headed superalkalide ion pairs, Kδ−[AE+@HMHC]Kδ− (AE = Ca and Sr), as stable and high-performance single-pole double-throw mid-far-infrared NLO molecular switches

K δ − [AE + @HMHC]K δ − may be as single-pole double-throw (SPDT) NLO molecular switch for novel electronic devices.