Table 2. Relative energies of several low-lying electronic states of [Fe(O)(Por⁺˙)]⁺ (A) ^a .

State	Configuration	A b	A c	A d
		ΔE + ZPE	ΔE + ZPE	ΔE + ZPE
2A1u	δ2 π*xz↑ π*yz↑ a1u↓	0.00	0.00	0.00
4A1u	δ2 π*xz↑ π*yz↑ a1u↑	0.71	0.19	0.21
2A2u	δ2 π*xz↑ π*yz↑ a2u↓	1.65	3.75	3.80
4A2u	δ2 π*xz↑ π*yz↑ a2u↑	1.25	3.42	3.47
6A2u	δ↑ π*xz↑ π*yz↑ σ*xy↑ a2u↑	9.25	18.68	19.38
4Δxy	δ↑ π*xz↑ π*yz↑ σ*xy↑ a1u↓	9.69	ND	ND
4Δzz	δ↑ π*xz↑ π*yz↑ σ*z2↑ a2u↓	19.53	ND	ND

^aRelative energies in kcal mol^–1 with respect to the ²A_1u state, ND stands for not determined.

^bEnergies obtained at UB3LYP/BS2//UB3LYP/BS1 level of theory.

^cEnergies and geometries calculated at UB3LYP/BS2 level of theory.

^dEnergies and geometries calculated at UB3LYP-D3/BS2 level of theory.