1A single butane
2  4
3    1BUT     C1    1   1.382   1.573   1.482
4    1BUT     C2    2   1.281   1.559   1.596
5    1BUT     C3    3   1.292   1.422   1.663
6    1BUT     C4    4   1.189   1.407   1.775
7   2.46298   2.46298   2.46298
8