Table 4.

TD-DFT calculated transition energies ν_calc (cm^-1), oscillator strength (f), composition (%) and dominant one-electron excitation of relevant Fe^IV d-d transitions in (a) mono-μ-oxo; (b) μ-oxo/μ-hydroxo and (c) bis-μ-oxo structures.

(a) mono-μ-oxo
νcalc (cm-1)	f	%	FeIV one-electron excitation
11 871	0.0010	62	xy (β 131) → z2 (β 135)
18 021	0.0017	41	xz (β 130) → z2 (β 135)
21 404	0.0008	69	yz (β 124) → z2 (β 135)
25 562	0.0007	55	x2-y2 (β 121) → z2 (β 135)
(b) μ-oxo/μ-hydroxo
νcalc (cm-1)	f	%	FeIV one-electron excitation
11 946	0.0027	64	xy (β 120) → z2 (β 124)
17 905	0.0011	46	xz (β 119) → z2 (β 124)
19 512	0.0053	55	yz (β 116) → z2 (β 124)
21 730	0.0022	18	x2-y2 (β 114) → z2 (β 124)
(c) bis-μ-oxo
νcalc (cm-1)	f	%	FeIV one-electron excitation
11 858	0.0003	83	z2 (β 120) → xy (β 124)
17 507	0.0017	42	xz (β 119) → xy (β 124)
18 660	0.0001	83	yz (β 118) → xy (β 124)
19 283	0.0005	76	x2-y2 (β 117) → xy (β 124)