<p>Physics-inspired Artificial Intelligence (AI) is at the forefront
of methods development in molecular modeling and computational chemistry. In
particular, interatomic potentials derived with Machine Learning algorithms
such as Deep Neural Networks (DNNs), achieve the accuracy of high-fidelity quantum
mechanical (QM) methods in areas traditionally dominated by empirical force
fields and allow performing massive simulations. The applicability domain of DNN
potentials is usually limited by the type of training data. As such, transferable
models are aimed to be extensible in the description of chemical and
conformational diversity of organic molecules. However, most DNN potentials,
such as the AIMNet model we proposed previously, were parametrized for neutral molecules
or closed-shell ions due to architectural limitations. In this work, we extend our
AIMNet framework toward open-shell anions and cations. This model explores a new
dimension of transferability by adding the charge-spin space. The resulting AIMNet
model is capable of reproducing reference QM energies for cations, neutrals and
anions with errors of 4.1, 2.1, 2.8 kcal/mol, respectively, compared to the
reference QM simulations. The spin-charges have errors 0.01-0.06 electrons for
small organic molecules containing nine chemical elements {H, C, N, O, F, Si, P,
S and Cl}. Thus the proposed AIMNet model allows researchers to fully bypass QM
calculations and derive the ionization potential, electron affinity, and
conceptual Density Functional Theory quantities like electronegativity,
hardness, and condensed Fukui functions. We show that these descriptors, along
with learned atomic representations, could be used to model chemical reactivity
through an example of regionselectivity in electrophilic aromatic substitution
reactions.</p>