# 22. 2D frequency fingerprints

## Definition

2D frequency fingerprint descriptors calculate the frequency if there is a relevant bond but calculate it to be zero(0) if there is not. Here, the fingerprints are binary vectors that indicate "1" if each bit has a specific substructural fragment in the molecule, and "0" if not.

## Relevant descriptors

No. Descriptor 1 frequency of C - C at topological distance 1 2 frequency of C - N at topological distance 1 3 frequency of C - O at topological distance 1 4 frequency of C - S at topological distance 1 5 frequency of N - N at topological distance 1 6 frequency of N - O at topological distance 1 7 frequency of N - S at topological distance 1 8 frequency of O - O at topological distance 1 9 frequency of O - S at topological distance 1 10 frequency of S - S at topological distance 1 11 frequency of C - C at topological distance 2 12 frequency of C - N at topological distance 2 13 frequency of C - O at topological distance 2 14 frequency of C - S at topological distance 2 15 frequency of N - N at topological distance 2 16 frequency of N - O at topological distance 2 17 frequency of N - S at topological distance 2 18 frequency of O - O at topological distance 2 19 frequency of O - S at topological distance 2 20 frequency of S - S at topological distance 2 21 frequency of C - C at topological distance 3 22 frequency of C - N at topological distance 3 23 frequency of C - O at topological distance 3 24 frequency of C - S at topological distance 3 25 frequency of N - N at topological distance 3 26 frequency of N - O at topological distance 3 27 frequency of N - S at topological distance 3 28 frequency of O - O at topological distance 3 29 frequency of O - S at topological distance 3 30 frequency of S - S at topological distance 3 31 frequency of C - C at topological distance 4 32 frequency of C - N at topological distance 4 33 frequency of C - O at topological distance 4 34 frequency of C - S at topological distance 4 35 frequency of N - N at topological distance 4 36 frequency of N - O at topological distance 4 37 frequency of N - S at topological distance 4 38 frequency of O - O at topological distance 4 39 frequency of O - S at topological distance 4 40 frequency of S - S at topological distance 4 41 frequency of C - C at topological distance 5 42 frequency of C - N at topological distance 5 43 frequency of C - O at topological distance 5 44 frequency of C - S at topological distance 5 45 frequency of N - N at topological distance 5 46 frequency of N - O at topological distance 5 47 frequency of N - S at topological distance 5 48 frequency of O - O at topological distance 5 49 frequency of O - S at topological distance 5 50 frequency of S - S at topological distance 5 51 frequency of C - C at topological distance 6 52 frequency of C - N at topological distance 6 53 frequency of C - O at topological distance 6 54 frequency of C - S at topological distance 6 55 frequency of N - N at topological distance 6 56 frequency of N - O at topological distance 6 57 frequency of N - S at topological distance 6 58 frequency of O - O at topological distance 6 59 frequency of O - S at topological distance 6 60 frequency of S - S at topological distance 6 61 frequency of C - C at topological distance 7 62 frequency of C - N at topological distance 7 63 frequency of C - O at topological distance 7 64 frequency of C - S at topological distance 7 65 frequency of N - N at topological distance 7 66 frequency of N - O at topological distance 7 67 frequency of N - S at topological distance 7 68 frequency of O - O at topological distance 7 69 frequency of O - S at topological distance 7 70 frequency of S - S at topological distance 7 71 frequency of C - C at topological distance 8 72 frequency of C - N at topological distance 8 73 frequency of C - O at topological distance 8 74 frequency of C - S at topological distance 8 75 frequency of N - N at topological distance 8 76 frequency of N - O at topological distance 8 77 frequency of N - S at topological distance 8 78 frequency of O - O at topological distance 8 79 frequency of O - S at topological distance 8 80 frequency of S - S at topological distance 8 81 frequency of C - C at topological distance 9 82 frequency of C - N at topological distance 9 83 frequency of C - O at topological distance 9 84 frequency of C - S at topological distance 9 85 frequency of N - N at topological distance 9 86 frequency of N - O at topological distance 9 87 frequency of N - S at topological distance 9 88 frequency of O - O at topological distance 9 89 frequency of O - S at topological distance 9 90 frequency of S - S at topological distance 9 91 frequency of C - C at topological distance 10 92 frequency of C - N at topological distance 10 93 frequency of C - O at topological distance 10 94 frequency of C - S at topological distance 10 95 frequency of N - N at topological distance 10 96 frequency of N - O at topological distance 10 97 frequency of N - S at topological distance 10 98 frequency of O - O at topological distance 10 99 frequency of O - S at topological distance 10 100 frequency of S - S at topological distance 10