Fitting parameters obtained from heating and cooling experiments under various conditions, with the heat rate θ, the LIESST temperature TLIESST, the relaxation rate constants associated with tunneling at low temperatures kHL(T → 0) or with the thermally activated relaxation k∞. The tunneling rate constants with their respective errors must be considered as an upper limit, since lower values down to zero gave similar results.
| Method | Condition | θ/(K min−1) | T LIESST/K | E a/cm−1 | k HL(T → 0)/s−1 | k ∞/s−1 |
|---|---|---|---|---|---|---|
| SQUID | — | 1.0 | 52 | 118 ± 7 | (0 ± 6.4) × 10−6 | (2.7 ± 0.6) × 10−2 |
| NEXAFS | Darkness | 1.2 | 52 | 124 ± 11 | (6.0 ± 1.6) × 10−5 | (3.6 ± 1.1) × 10−2 |
| Const. illum. | −0.6 | — | 170 ± 13 | (3.6 ± 1.8) × 10−4 | 2.1 ± 0.8 | |
| UV/vis | Intensity | 3.1 | 46 | 99 ± 32 | (7.6 ± 0.9) × 10−4 | (3.9 ± 3.3) × 10−2 |
| Area | 52 | 131 ± 53 | (6.7 ± 0.7) × 10−4 | 0.1 ± 0.1 |