new index atom name original index 1 C 10 2 C 13 3 C 6 4 C 9 5 C 8 6 C 7 7 C 14 8 C 11 9 C 12 10 N 5 11 O 3 12 O 1 13 O 2 14 O 4 15 H 19 16 H 20 17 H 15 18 H 16 19 H 18 20 H 17 21 H 21 22 H 22 23 H 25 24 H 23 25 H 24