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