Table 2.

Computational data (at the scalar‐relativistic x2c‐TZVPall/TPSSh functional level) of compounds 3–5 (M=Ge, Sn, Pb).

	3	4	5
WBI (C−P)	1.33	1.34	1.38
WBI (P−M)	1.20	1.13	1.08
λ max abs [nm]	507	528	539