new index atom name original index 1 C 13 2 C 14 3 C 11 4 C 5 5 C 8 6 C 12 7 C 9 8 C 15 9 C 7 10 C 4 11 C 10 12 C 6 13 N 3 14 N 2 15 O 1 16 H 24 17 H 25 18 H 26 19 H 27 20 H 22 21 H 16 22 H 17 23 H 18 24 H 19 25 H 23 26 H 21 27 H 20