. 2015 May 6;5:9870. doi: 10.1038/srep09870

Table 2. Hardness (GPa), computed by the macroscopic Chen model, bulk modulus B (GPa), shear modulus G (GPa), Young's modulus E (GPa), k²G (k = G/B) and Poisson's ratio v for diamond and the stable C-N phases at zero pressure.

Structures	B	G	E	k ² G	v	H_Chen
Diamond	434.9	520.6	1116.4	748.4	0.0722	92.9
	398.3	351.5	814.9	274.1	0.1589	50.3
P31c-C₃N₄	383.6	330.6	770.4	245.5	0.1653	47.0
Cm-C₃N₄	353.6	328.3	752.1	283.0	0.1455	51.4
	372.0	345.8	791.9	298.8	0.1452	53.1
	436.6	374.4	873.4	275.2	0.1666	50.5
Cmc2₁-C₃N₄	347.1	335.1	760.5	312.2	0.1348	54.6
P4₂/m-CN	326.8	272.7	640.1	189.8	0.1736	40.0
Pnnm-CN	338.6	327.0	742.2	305.0	0.1347	53.8

Table 2. Hardness (GPa), computed by the macroscopic Chen model, bulk modulus B (GPa), shear modulus G (GPa), Young's modulus E (GPa), k2G (k = G/B) and Poisson's ratio v for diamond and the stable C-N phases at zero pressure.