Table 2. Activation barriers (eV) for the temperature-dependent non-radiative channels (see Scheme 1) and prefactor x for 1–6.

Complex	E a	E b	E c	E lim a	x
1	0.287	0.064	0.075	0.298 b	1
2	0.272	0.096	0.077	0.272	0.91
3	0.136	0.200	0.067	0.136	0.46
4	0.000	0.307	0.042	0.042	0.14
5	0.000	0.348	0.060	0.060	0.20
6	0.252	0.118	0.088	0.252	0.85

^aThe E_lim value usually corresponds to E_a or E_c value, depending on the kinetic scenario.

^bFor 1, since the MECP barrier is above the TS barrier, E_lim is obtained according to E_lim = E_a + E_c – E_b.