Table 2. The DFT/PBE calculated and experimental Ln–C_centroid (Cnt) distances (Å) from Ln^III(C₅H₄SiMe₃)₃ and Ln^II(C₅H₄SiMe₃)₃ ^1– (Ln = Sm, Ho). Structural metrics from Ho^II(C₅H₄SiMe₃)₃ ^1– with 4f¹⁰ 5d¹ versus 4f¹¹ 5d⁰ electronic configurations were also compared.

Sm(C5H4SiMe3)3 x– (x = 0, 1)
	SmIII, 4f5 5d0		SmII, 4f6 5d0		Δ(SmII–SmIII)
	PBE	Exp8a	PBE	Exp8a	PBE	Exp8a
Sm–Cnt1	2.508	2.459	2.610	2.603	0.102	0.144
Sm–Cnt2	2.512	2.459	2.595	2.607	0.083	0.148
Sm–Cnt3	2.519	2.464	2.609	2.615	0.090	0.151
Avg(Sm–Cnt)	2.513	2.461	2.605	2.608	0.092	0.147

Ho(C5H4SiMe3)3 x– (x = 0, 1)
	HoIII, 4f10 5d0		HoII, 4f10 5d1		HoII, 4f11 5d0	Δ[HoII (4f10 5d1)–HoIII]
	PBE	Exp1b	PBE	Exp1b	PBE	PBE	Exp1b
Ho–Cnt1	2.438	2.391	2.477	2.417	2.536	0.039	0.026
Ho–Cnt2	2.441	2.393	2.461	2.420	2.509	0.020	0.027
Ho–Cnt3	2.448	2.398	2.481	2.432	2.517	0.033	0.034
Avg(Ho–Cnt)	2.442	2.394	2.473	2.423	2.521	0.031	0.029