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