type: Hooke

references:
  - J.R. Neighbours and G.A. Alers,
    Physical Review 111:707-712, 1958,
    https://doi.org/10.1103/PhysRev.111.707
  - Y.A. Chang and L. Himmel,
    Journal of Applied Physics 37:3567-3572, 1966,
    https://doi.org/10.1063/1.1708903

C_11: 122.9e+9
C_11,T: -313.5e+5
C_11,T^2: -107.3e+2

C_12: 91.55e+9
C_12,T: -164.1e+5
C_12,T^2: -681.6e+1

C_44: 42.63e+9
C_44,T: -180.5e+5
C_44,T^2: -353.8e+1

T_ref: 300