Polarization of Electron Density Databases of Transferable Multipolar Atoms

Polarizability
is a key molecular property involved in either macroscopic
(i.e., dielectric constant) and microscopic properties (i.e., interaction
energies). In rigid molecules, this property only depends on the ability
of the electron density (ED) to acquire electrostatic moments in response
to applied electric fields. Databases of transferable electron density
fragments are a cheap and efficient way to access molecular EDs. This
approach is rooted in the relative conservation of the atomic ED between
different molecules, termed transferability principle. The present
work discusses the application of this transferability principle to
the polarizability, an electron density-derived property, partitioned
in atomic contributions using the Quantum Theory of Atoms In Molecules
topology. The energetic consequences of accounting for in situ deformation
(polarization) of database multipolar atoms are investigated in detail
by using a high-quality quantum chemical benchmark.