2 Properties

Table 10.2: Energies relative to diamond ( $\delta$ E), bulk moduli (B $_0$ ), volumes(V), hardnesses(H) for the investigated structures. GW band gaps are shown in curly brackets.

Allotropes	$\delta$ E	B $_0$	V	H	Band gap
	eV/atom	GPa	$^3$ /atom	GPa	eV
diamond	0	431.1	5.70	89.7	4.2 {5.4}
lonsdaleite	0.024	437.3	5.71	89.1	3.6 {5.0}
M-carbon	0.159	392.7	5.95	84.3	3.6 {5.0}
W-carbon	0.154	409.4	5.95	84.8	4.0
bct C $_4$	0.197	404.9	5.97	84.0	2.7 {3.8}
X-carbon	0.182	404.0	6.02	83.2	3.8
Y-carbon	0.207	408.2	5.84	83.5	2.9
X+D	0.135	409.0	5.90	76.2	4.4
M+D	0.103	427.0	5.84	79.1	4.3
B+D	0.096	417.0	5.81	86.6	3.4