new index atom name original index 1 C 14 2 C 8 3 C 9 4 C 10 5 C 11 6 C 6 7 C 13 8 C 7 9 C 12 10 N 5 11 O 4 12 O 2 13 O 3 14 O 1 15 H 30 16 H 29 17 H 31 18 H 19 19 H 20 20 H 18 21 H 22 22 H 23 23 H 21 24 H 25 25 H 24 26 H 26 27 H 27 28 H 28 29 H 15 30 H 16 31 H 17