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