Just to make sure the explanation made is understood, i 'll use an example.

so in the example below, one always read along a row with a donor index followed by an acceptor index, donor then acceptor kind of fashion.

so atom 1 and 5, 2 and 1, 3 and 1 are examples of donor/acceptor pairs?

30279 !NBOND: bonds
1 5 2 1 3 1 4 1
5 6 7 5 7 8 7 9
10 7 10 11 10 12 13 10
13 14 13 15 16 13 16 17
16 18 19 16 19 20 19 21
19 22 23 5 23 25 24 23
25 26 25 27 27 28 29 27
29 30 31 29 31 32 31 33
31 34 35 29 35 36 35 37
35 38 39 27 39 41 40 39
41 42 41 43 43 44 45 43
45 46 45 47 48 45 49 48
49 50 51 49 51 52 53 51


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