new index	atom name	original index
1	C	1
2	C	6
3	C	3
4	C	8
5	C	4
6	C	7
7	C	2
8	C	5
9	H	9
10	H	11
11	H	10
12	H	14
13	H	15
14	H	16
15	H	12
16	H	18
17	H	13
18	H	17
