Table 1.

Thermoelastic properties of diamond and coesite

Parameter	Designation	Units	Diamond	Coesite
Bulk modulus	Ko = −V(dP/dV)T	GPa	442†	99.8‡
Its pressure derivative	K′o = (dKo/dP)T		4†	6.3‡
Its temperature derivative	(dKo/dT)P	GPa/K	−0.0188†	−0.020§
Shear modulus	μd	GPa	538†
Thermal expansivity	α = 1/V(dV/dT)P = a + bT + cT2 + dT3	1/K
Coefficients in equation for α	a*106		6.828¶	5.43‖
	b*106		0.042¶	0.005‖
	c*1010		−0.309¶	0
	d*1015		8.88¶
Raman shift vs. pressure	dν/dP	cm−1/GPa		2.9 (±0.1)‡‡

The ΔV/V term at constant temperature, for both diamond and coesite, can be found from a simple Murnaghan equation of state, P = K′_o/K_o[(V_o/V)^K_o + 1], where K(P) = K_o + K′_oP and K(T) = K_o + (dK/dT)dT. The temperature dependence of the diamond bulk modulus is below the error limits and can be effectively neglected. The pressure dependence of thermal expansivity may also be neglected, especially taking into account the very small difference in thermal expansion between coesite and diamond. 

^†Ref. 51. 

^‡Refs. 32 and 33. 

^§Ref. 53. 

^¶Ref. 54. 

^‖Ref. 52. 

^‡‡Ref. 27.