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