PIEZOELECTRIC CRYSTALS IN TENSOR FORM 



119 



Class 16 



Class 18 



Class 19 



Class 22 



dn —dn du dn —Id^i 

 — dvt d^i </i5 —du —2dn 

 dn dsi d33 



^u -dn du 



-du -2dn 







dn -dn -2^22 

 -da (/22 -2dn 

 



^11 -dn 

 -2dn 







(138) 



5.3 Fourth Rank Tensors of the Elastic Type for the Crystal Classes 



