Planar tetracoordinate carbon molecules with 14 valence electrons: examples of CBe4Mnn−2 (M = Li, Au; n = 1–3) clustersElectronic supplementary information (ESI) available: Cartesian coordinates for optimized GM clusters 1–6 of CBe4Mnn−2 (M = Li, Au; n = 1–3) and their three lowest-lying isomers (nB–nD) at PBE0-D3/def2-TZVPP (Table S1); orbital composition analysis for CBe4Li− (1) and CBe4Au− (4), along with the LUMOs of CBe4M3+ (M = Li, Na, K, Cu, Ag, Au) (Tables S2–S4); optimized geometries of GM clusters 1–6 and their lowest-lying isomers nB–nD (Fig. S1); natural atomic charges of 1–6 (Fig. S2); root-mean-square deviations of 1–6 during their molecular dynamics simulations (Fig. S3); CMO pictures of 1/4 (Fig. S4); optimized tetrahedral carbon (thC) structures of 1′/3′/4′ at the PBE0-D3/def2-TZVPP level (Fig. S5); comparison of Wiberg bond indices (WBIs) and natural atomic charges of GM ptC cluster 3 and thC isomer 3′ (Fig. S6); and calculated nucleus-independent chemical shifts for 1–6 (Fig. S7). See DOI: 10.1039/d0nj03944f

Planar tetracoordinate carbon molecules with 14 valence electrons: examples of CBe4Mnn−2 (M = Li, Au; n = 1–3) clustersElectronic supplementary information (ESI) available: Cartesian coordinates for optimized GM clusters 1–6 of CBe4Mnn−2 (M = Li, Au; n = 1–3) and their three lowest-lying isomers (nB–nD) at PBE0-D3/def2-TZVPP (Table S1); orbital composition analysis for CBe4Li− (1) and CBe4Au− (4), along with the LUMOs of CBe4M3+ (M = Li, Na, K, Cu, Ag, Au) (Tables S2–S4); optimized geometries of GM clusters 1–6 and their lowest-lying isomers nB–nD (Fig. S1); natural atomic charges of 1–6 (Fig. S2); root-mean-square deviations of 1–6 during their molecular dynamics simulations (Fig. S3); CMO pictures of 1/4 (Fig. S4); optimized tetrahedral carbon (thC) structures of 1′/3′/4′ at the PBE0-D3/def2-TZVPP level (Fig. S5); comparison of Wiberg bond indices (WBIs) and natural atomic charges of GM ptC cluster 3 and thC isomer 3′ (Fig. S6); and calculated nucleus-independent chemical shifts for 1–6 (Fig. S7). See DOI: 10.1039/d0nj03944f