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