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