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