new index	atom name	original index
1	C	1
2	C	2
3	C	3
4	C	4
5	C	5
6	C	6
7	C	7
8	C	8
9	N	9
10	O	10
11	H	11
12	H	12
13	H	13
14	H	14
15	H	15
16	H	16
17	H	17
18	H	18
19	H	19
20	H	20
21	H	21