Table 2.
Free energies in kcal/mol (including dielectric effects) for the splitting between the experimental ground state of the reactant S=3/2 (1α2α) and the calculated ground state S=1/2 (5α4β). (a) The amount of Hartree-Fock exchange in B3LYP is 20%, for B3LYP* it is 15%, and for the other functionals presented here it was set to 10%, 5% and 0%, respectively. BLYP is not a hybrid functional and contains no Hartree-Fock exchange.
| State | Mulliken Spin | ΔE | HAT versus | |||||
|---|---|---|---|---|---|---|---|---|
| Functional(a) | Fe1(III) | Fe2(IV) | S | Fe1 | Fe2 | Reactants | ground state | own spin state |
| B3LYP |
1α 5α |
2α 4β |
3/2 1/2 |
0,84 4,10 |
1,56 -3,38 |
9,5 0,0 |
47,1 22,0 |
37,6 22,0 |
| B3LYP* |
1α 5α |
2α 4β |
3/2 1/2 |
0,94 3,98 |
1,30 -3,15 |
2,7 0,0 |
44,9 24,7 |
42,2 24,7 |
| B3LYPX10 |
1α 5α |
2α 4β |
3/2 1/2 |
0,90 3,94 |
1,39 -3,04 |
0,0 4,6 |
44,5 31,2 |
44,5 26,6 |
| B3LYPX5 |
1α 5α |
2α 4β |
3/2 1/2 |
0,94 3,87 |
1,33 -2,93 |
0,0 10,8 |
46,6 39,0 |
46,6 28,2 |
| B3LYPX0 |
1α 5α |
2α 4β |
3/2 1/2 |
1,08 3,73 |
1,16 -2,76 |
0,0 22,6 |
47,5 52,6 |
47,5 30,0 |
| BLYP |
1α 5α |
2α 4β |
3/2 1/2 |
0,97 3,84 |
1,22 -2,90 |
0,0 18,9 |
39,3 35,7 |
39,3 16,8 |