. 2024 Feb 28;15(13):4981–4988. doi: 10.1039/d4sc00165f

Selected bond lengths from crystallographic and DFT-optimized structures (M06-L functional) for the [M₄E₁₈]⁴⁻ family (all distances in Å).

		E _rel/eV	M1–M2	M2–M2′	M1–E3	M2–E9	E2–E6	E5–E9′	E7–E8′	Ref
[Fe₄Sn₁₈]⁴⁻	X-ray (100 K)		2.413	2.496	2.828	2.739	3.142	3.225	4.898	This work
	DFT (⁹A_g)	0.59	2.41	2.47	2.90	2.75	3.17	3.18	4.89
	DFT (¹¹B_1g)	0.0	2.42	2.31	2.90	2.79	3.20	3.19	4.88
	DFT (¹¹B_3g)	0.05	2.41	2.52	2.88	2.75	3.17	3.24	4.86
	DFT (¹³B_2g)	0.25	2.43	2.63	2.94	2.75	3.14	3.27	5.06
[Fe₄Pb₁₈]⁴⁻	X-ray (100 K)		2.437	2.328	2.974	2.892	3.247	3.287	4.941	This work
	DFT (⁹B_1u)	0.79	2.41	2.46	2.99	2.90	3.32	3.37	4.99
	DFT (¹¹B_1g)	0.0	2.44	2.28	3.03	2.90	3.35	3.32	4.99
	DFT (¹¹B_3g)	0.18	2.43	2.48	3.00	2.86	3.32	3.36	4.98
	DFT (¹³B_3g)	0.18	2.46	2.35	3.01	2.86	3.34	3.37	5.05
[Cu₄Sn₁₈]⁴⁻	X-ray (100 K)		2.525	2.631	2.842	2.760	3.108	3.219	4.915	31
[Cu₄Sn₁₈]⁴⁻	DFT (¹A_g)		2.52	2.58	2.86	2.76	3.14	3.24	4.91	31
[Cu₄Pb₁₈]⁴⁻	X-ray (100 K)		2.547	2.561	2.935	2.825	3.224	3.299	5.012	31
[Cu₄Pb₁₈]⁴⁻	DFT (¹A_g)		2.55	2.52	2.99	2.88	3.30	3.35	5.02	31

Selected bond lengths from crystallographic and DFT-optimized structures (M06-L functional) for the [M4E18]4− family (all distances in Å).