Partial atomic charges can be used to quantify the degree of ionic versus covalent bonding of any compound across the periodic table.
The necessity for such quantities arises, for example, in molecular simulations to compute bulk and surface properties in agreement with experiment.
[3] Atomic charges for a given compound can be derived in multiple ways, such as: The discussion of individual compounds in prior work has shown convergence in atomic charges, i.e., a high level of consistency between the assigned degree of polarity and the physical-chemical properties mentioned above.
[5][6] Only as recently as 2016 was a method for theoretically computing partial atomic charges developed that performs consistently well across an extremely wide variety of material types.
[5][6] All of the earlier methods had fundamental deficiencies that prevented them from assigning accurate partial atomic charges in many materials.
[5][6] Mulliken and Löwdin partial charges are physically unreasonable, because they do not have a mathematical limit as the basis set is improved towards completeness.