Table 2. Relative Energies and Expectation Values of S² of Different Low-Lying States of [Cu(L1)₂]⁺ and [Cu(L2)₂]⁺ by Density Functional Calculations with the B3LYP and TPSSh Functionals and the def2-TZVP Basis Set (including the D3 Dispersion Correction) and the Mulliken Spin Populations (SP) on the Copper atom^a.

		B3LYP + D3				TPSSh + D3
complex	state	E/eV	⟨S2⟩	J/cm–1	SP(Cu)	E/eV	⟨S2⟩	J/cm–1	SP (Cu)
[Cu(L1)2]+	3A	0	2.02		0.16	0	2.02		0.26
	BSA	0.012	1.00	131	0.00	0.037	0.97	280	0.00
	1ARKS	0.321	0		0	0.197	0		0
[Cu(L2)2]+	3A	0	2.03		0.22	0	2.02		0.28
	BSA	0.023	0.97	243	0.00	0.041	0.95	313	0.00
	1ARKS	0.253	0		0	0.146	0		0

^aBSA denotes the broken-symmetry state, ¹A^RKS denotes the closed-shell singlet state by restricted Kohn–Sham calculations. Additionally, the table presents the coupling constants J of the Heisenberg-Dirac-van-Vleck Hamiltonian , representing the singlet triplet splitting and was performed in the broken-symmetry geometry. The values are obtained according to the formula of Soda et al.³⁸