Table 4. Comparison between the Predicted Activation Energies and Conductivities (Computed at 500 K and Extrapolated at Room Temperature; See SI for Details) of the β and α Phases with Both Experimental References28,96 and Previous ab initio MD Studies22,114,115.
| EβA (eV) | EαA (eV) | σβ298K (S cm–1) | σβ500K (S cm–1) | σα298K (S cm–1) | |
|---|---|---|---|---|---|
| PBEsol | 0.38 | 0.17 | 7.7 × 10–4 | 2.8 × 10–1 | 1.9 × 10–1 |
| r2SCAN | 0.57 | 0.21 | 2.1 × 10–5 | 5.1 × 10–2 | 9.2 × 10–2 |
| PBE0 | 0.62 | 0.19 | 8.7 × 10–6 | 3.9 × 10–2 | 1.6 × 10–1 |
| exp. | 0.47 [96], 0.36 [28] | 0.22 [28] | 8.9 × 10–7 [96,113] | 3.0 × 10–2 [20] | |
| AIMD-PBE | 0.40 [22] | 0.18 [114] | 8.0 × 10–2 [114] |