Self-returning walk atomic code

For the i th atom of a molecule, the sequence of atomic self-returning walk counts of increasing length up to A defines the self-returning walk atomic code (Sf Wy4C) ... 

By summing all the entries of the self-returning walk atomic code, a different local invariant called vertex structural code (SC, or structural code) is obtained ... 

KSC = Kekule structure count QSAR = quantitative structure-activity relationships QSPR = quantitative structure-property relationships SRWAC = self-returning walk atomic code TEMO = topological effect on molecular orbitals TRE = topological resonance energy TREPE = TRE per r-electron. 

Graphs with identical atomic codes for all the vertices, i.e. there exists a one-to-one correspondence between the atomic codes of all vertices. The most well-known atomic codes are -> walk count atomic code, - self-returning walk count atomic code, - atomic path code. 

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