  The simulation of intrinsic contributions to molecular properties holds the
potential to allow for chemistry to be directly inferred from changes to
electronic structures at the atomic level. In the present study, we demonstrate
how such local properties can be readily derived from suitable molecular
orbitals to yield effective fingerprints of various types of atoms in organic
molecules. In contrast, corresponding inferences from schemes that instead make
use of individual atomic orbitals for this purpose are generally found to fail
in expressing much uniqueness in atomic environments. By further studying the
extent to which entire chemical reactions may be decomposed into meaningful and
continuously evolving atomic contributions, schemes based on molecular rather
than atomic orbitals are once again found to be the more consistent, even
allowing for intricate differences between seemingly uniform nucleophilic
substitutions to be probed.
