Incorrect symmetry in piezoelectric tensor
Posted: Tue Dec 17, 2013 9:32 pm
Hello, I recently ran some computations to determine the piezoelectric coefficients for four compounds. Two of them were rhombohedral (space group R32) and the other two were orthorhombic (sg Imm2). The tensor for a rhombohedral compound should be
d11 -d11 0 d14 0 0
0 0 0 -d14 0 -2*d11
0 0 0 0 0 0
The tensors I computed however, looks like
d11 -d11 0 d14 0 0
0 0 0 -d14 0 -d11
0 0 0 0 0 0
It seems as though there is a factor of 2 missing. Is there a way to correct this? The Imm2 tensors came out correct.
Thank you for any assistance.
d11 -d11 0 d14 0 0
0 0 0 -d14 0 -2*d11
0 0 0 0 0 0
The tensors I computed however, looks like
d11 -d11 0 d14 0 0
0 0 0 -d14 0 -d11
0 0 0 0 0 0
It seems as though there is a factor of 2 missing. Is there a way to correct this? The Imm2 tensors came out correct.
Thank you for any assistance.