#Elastic constants of PbS (GPa) from Anderson, Physical Acoustics 1965 (measured at 293 K)
126.9 29.7 29.7 0 0 0
29.7 126.9 29.7 0 0 0
29.7 29.7 126.9 0 0 0
0 0 0 24.8 0 0
0 0 0 0 24.8 0
0 0 0 0 0 24.8
