Table 1. Bonding Energy per Atom (Eb), the Second-Order Difference Energy (Δ2E), HOMO–LUMO Energy Gap (Egap), the Lowest Vibrational Frequency, VIP, and VEA in the Ground-State Isomers of NbMgn (n = 2–12) Clusters.
| isomer | Eb (eV) | Δ2E (eV) | Egap-α (eV) | Egap-β (eV) | lowest Freq (cm–1) | VIP (eV) | VEA (eV) | KS-gap (eV) | F-gap (eV) |
|---|---|---|---|---|---|---|---|---|---|
| NbMg2 | 0.35 | 1.31 | 3.38 | 33 | 5.29 | 0.78 | 4.69 | 4.51 | |
| NbMg3 | 0.53 | 0.15 | 1.40 | 2.56 | 86 | 5.48 | 1.19 | 3.96 | 4.29 |
| NbMg4 | 0.61 | 0.14 | 1.41 | 2.22 | 64 | 5.30 | 1.31 | 3.63 | 3.99 |
| NbMg5 | 0.64 | –0.20 | 1.59 | 1.56 | 44 | 5.17 | 0.98 | 3.14 | 4.19 |
| NbMg6 | 0.69 | –0.71 | 1.76 | 1.48 | 13 | 4.85 | 0.85 | 3.24 | 4.00 |
| NbMg7 | 0.81 | 0.71 | 1.11 | 2.15 | 18 | 4.25 | 1.21 | 3.26 | 3.05 |
| NbMg8 | 0.83 | 1.03 | 1.13 | 1.39 | 7 | 4.42 | 0.91 | 2.52 | 3.51 |
| NbMg9 | 0.74 | –1.11 | 1.01 | 1.77 | 39 | 4.59 | 1.85 | 2.78 | 2.73 |
| NbMg10 | 0.77 | –0.24 | 1.14 | 1.93 | 35 | 4.53 | 1.35 | 3.07 | 3.17 |
| NbMg11 | 0.81 | 0.38 | 1.05 | 1.11 | 11 | 4.39 | 1.32 | 2.17 | 3.07 |
| NbMg12 | 0.82 | 1.06 | 1.09 | 40 | 4.42 | 1.56 | 2.15 | 2.86 |