Table 1. Spin Hamiltonian parameters for simulating the cw EPR spectra of 1′–4′.

	1′	2′	3′	4′ a
g ∥	1.9878	2.085	1.950	2.082
g ⊥ b	1.9698	2.019	1.960	2.018
	1.9698	2.019	1.955	2.018
A ∥ (MHz)	0 c	500	0 c	460 (140)
A ⊥ (MHz) b	258	115	255	145 (90)
	264	115	265	145 (90)
α 2	—	0.51	—	0.39
Spin density (M)	0.935	0.756	0.949	0.732
Spin density (E) d	0.008	0.059	0.007	0.065

^aHyperfine coupling constants in parentheses for 4′ correspond to ⁷⁷Se hyperfine coupling.

^bTop values for g_⊥ and A_⊥ are g_x and A_x, bottom values are g_y and A_y.

^cNo features in the EPR spectrum corresponding to A_∥ are apparent, inducing significant error in this value, and was held at zero for the simulation.

^dSpin densities at the metal (M) and S/Se donors (E) were calculated using CASPT2.