8
Staggered ethane has D3d symmetry
 1   0.000000000  -1.024342948   1.140400499
 6   0.000000000   0.000000000   0.756028963
 1  -0.887107016   0.512171474   1.140400499
 6  -0.000000000   0.000000000  -0.756028963
 1   0.887107016   0.512171474   1.140400499
 1  -0.887107016  -0.512171474  -1.140400499
 1   0.887107016  -0.512171474  -1.140400499
 1  -0.000000000   1.024342948  -1.140400499
