Table 2. Structural data for the GC under different pressures as calculated in this work, including mass density (density), the ratio of the C₂ dimer, twofold coordinated atoms (sp), threefold coordinated atoms (sp²), threefold coordinated atoms (sp³), mean bond length (R₁), average total coordination number (CN), bulk modulus (B), shear modulus (G) and Young's modulus (E). The theoretical results of bulk diamond are also shown for comparison.

Pressure (GPa)	Density (g/cm3)	C2 dimer (%)	sp (%)	sp2 (%)	sp3 (%)	R1 (Å)	CN	B (GPa)	G (GPa)	E (GPa)
0	1.88	9	12	72	7	1.463	2.86	97	36	96
3.61	2.09	9	10	70	11	1.462	2.95	111	62	156
6.56	2.35	12	3	60	25	1.470	3.10	138	87	216
8.46	2.50	13	0	53	34	1.476	3.23	150	101	248
9.86	2.68	9	0	49	42	1.496	3.43	240	154	381
18.49	2.89	11	0	44	45	1.488	3.4	256	152	389
30.3	3.13	15	0	32	53	1.485	3.49	315	215	525
55.9	3.48	13	0	12	75	1.48	3.7	416	270	666
58.3	3.54	13	0	9	78	1.48	3.72	434	314	759
79	3.75	11	0	0	89	1.475	3.78	521	368	893
diamond	3.52	0	0	0	100	1.54	4	447	540	1159