The charge density is an important physical quantity obtained from first-principles calculations based on density functional theory (DFT). Much useful information about the investigated materials can be extracted from it, such as chemical bonding, charge transfer, and orbital hybridization. Here I post this question to ask:
What can we learn by inspecting charge densities calculated with DFT?
Here is an example answer to this question following this paper:
The author compares the differential charge density accumulation between bilayer PtS$_2$ and MoS$_2$ and concludes the bilayer PtS$_2$ will host a more strong interlayer coupling due to the significant charge accumulation.