Table 2 The energy difference (ΔE, per unit, eV) between ZB and WZ polymorphs of GaAs, lattice constant, a, and bulk moduli B(GPa) of GaAs (ZB) and Ge (diamond)
From: On the Chemical Origin of the Gap Bowing in (GaAs)1−xGe2x Alloys: A Combined DFT–QSGW Study
GaAs (ZB) 216, F-43 m, Z = 4 | GaAs (WZ) 186, P 63 mc, Z = 2 | Ge (cubic) 227, Fd-3m, Z = 8 | |
|---|---|---|---|
This study, PAW/LDA | |||
ΔE | – | +0.06 | – |
B | 66.14 | 71.8 | |
Lattice constant (Å) | a = 5.605 | a = 3.917, b = 3.886c = 6.505 | a = 5.612 |
This study, PAW/GGA | |||
ΔE | – | +0.03 | – |
B | 79.01 | 71.0 | |
Lattice constant (Å) | a = 5.739 | a = 4.040, c = 6.668 | a = 5.747 |
Previous study (LDA) | |||
ΔE | – | +0.0120a | |
B | 75.7b, 77.1e | 73.3c, 79.4c | |
Lattice constant (Å) | a = 5.654a, 5.53b5.508e, 5.644k | a = 3.912, c = 6.441aa = 3.912, c = 6.407b | a = 5.58c, 5.53c |
Previous study (GGA) | |||
B | 59.96h | 55.9c | |
Lattice constant (Å) | a = 5.74h, 5.722i | a = 3.540, c = 6.308l | a = 5.78c |
Experimentally | |||
ΔE | – | +0.0117k | |
B | 77f | 75d | |
Lattice constant (Å) | a = 5.649f, 5.65g | a = 5.678j, 5.66d | |