1. Relative DFT Energies (meV cell–1) of the Geometries of the A+ Ions (A = Li, Na, K) at the Four Different Occupation Positions ((off-)FC/TH/BC) .
| occupation positions | Li+ | Na+ | K+ |
|---|---|---|---|
| FC | 0.0 | 150 | 3912 |
| off-FC | not converged | 0.0 | not converged |
| TH | 216 | 462 | not converged |
| BC | 1338 | 432 | 0.0 |
a
The energy scale is relative to the most stable occupation position for each A+ ion. We designate the label “not converge” for instances where the geometry optimization of the initial positions of the A+ ions, as specified in the first column, does not converge. In such cases, the optimized positions are found to be insufficiently close to the corresponding initial positions.
b
No imaginary vibrational modes for A+ ions.