1     6  Ethylene
2     1  C       2
3     2  C       2     1   1.33756
4     3  H       5     1   1.10243     2  120.8543
5     4  H       5     1   1.10243     2  120.8543     3  118.2914    -1
6     5  H       5     2   1.10243     1  120.8543     3    0.0000     0
7     6  H       5     2   1.10243     1  120.8543     5  118.2914    -1
8