type: Hooke

references:
  - G.A. Alers,
    Journal of Physics and Chemistry of Solids 13(1-2):40-55, 1960,
    https://doi.org/10.1016/0022-3697(60)90125-6,
    fit to Tab. 2 (T_min=100K, T_max=700K)

C_11: 251.0e+9
C_11,T: -4.998e+7
C_11,T^2: -2.952e+4

C_12: 150.0e+9
C_12,T: -4.269e+6
C_12,T^2: -6.429e+3

C_44: 123.7e+9
C_44,T: -3.618e+7
C_44,T^2: -7.024e+3

T_ref: 293.15