Structural and mechanical properties of cubic GaP at 0 K and 300 K evaluated by QHA in comparison with other DFT calculations [6,25] and experiments [18,19]. The lattice parameter (ao) is in Å, the mechanical properties (elastic constants (C11, C12, and C44), Bulk modulus (B), Shear modulus (G) and Young modulus (Y)) are in GPa, and the Poisson ratio (η) has no unit.

Table 1: Structural and mechanical properties of cubic GaP at 0 K and 300 K evaluated by QHA in comparison with other DFT calculations [6,25] and experiments [18,19]. The lattice parameter (a_o) is in Å, the mechanical properties (elastic constants (C₁₁, C₁₂, and C₄₄), Bulk modulus (_B), Shear modulus (_G) and Young modulus (_Y)) are in GPa, and the Poisson ratio (η) has no unit.

Properties	PBESOL (0 K)	PBESOL (300 K)	Ref [6] (0 K)	Ref [25] (0 K)	Exp. [18]	Exp. [19]
Lattice parameter (Å)	5.449	5.454	5.502	-	5.451	5.451
C₁₁ (GPa)	130.3	129.2	123	137.5	-	-
C₁₂ (GPa)	56.6	55.9	50.9	59.4	-	-
C₄₄ (GPa)	88.9	87.8	70.9	72.2	-	-
Bulk modulus (B) (GPa)	81.2	80.3	75.1	-	88.7	-
Shear modulus (G) (GPa)	68.1	67.4	54.2	-	-	-
Young modulus (Y) (GPa)	149.2	147.7	-	-	-	-
Poisson ratio (η)	0.1939	0.1937	-	-	-