A D4Rank3Tensor is a third rank tensor with
D4 point group symmetry. The argument d14 is a
real number. The '1' in the argument name is a space index (1, 2,
or 3) and the second is a Voigt index (1 through 6).
Figure 6.135. Structure of a D4 Third Rank Tensor
Structure of a D4 rank 3 tensor. For an explanation of
the symbols, see Figure 6.57.