new index atom name original index 1 C 8 2 C 6 3 C 9 4 C 5 5 C 4 6 C 7 7 C 10 8 O 1 9 O 2 10 O 3 11 H 13 12 H 12 13 H 14 14 H 11 15 H 15 16 H 16