According to density functional theory, any chemical property can be inferred
from the electron density, making it the most informative attribute of an
atomic structure. In this work, we demonstrate the use of established physical
methods to obtain important chemical properties from model-predicted electron
densities. We introduce graph neural network architectural choices that provide
physically relevant and useful electron density predictions. Despite not
training to predict atomic charges, the model is able to predict atomic charges
with an order of magnitude lower error than a sum of atomic charge densities.
Similarly, the model predicts dipole moments with half the error of the sum of
atomic charge densities method. We demonstrate that larger data sets lead to
more useful predictions in these tasks. These results pave the way for an
alternative path in atomistic machine learning, where data-driven approaches
and existing physical methods are used in tandem to obtain a variety of
chemical properties in an explainable and self-consistent manner