All DFT calculations were made using the exchange-correlation functionals PBE in combination with triple-zeta polarized basis sets (TZP) as implemented in BAND 2019. BAND have recently been developed to support direct output of 𝛸(𝒓), as approximated by Eq. ( ) (see the Supporting Information). Isolated atoms used as references in the evaluation of in situ electronegativity are calculated at the same level of theory and embedded in unit cells of size 8x8x8 Å for Li, C, N, O and F, and 10x10x10 Å for K and Ga. For atoms, 𝛸 can be straightforwardly calculated from Eq.( ) in terms of the total density of states (DOSs) referenced to vacuum, as explained in Ref. 33. For calculations of crystalline systems, lattice parameters have been set to equal experimental data (See Supporting Information), while all atomic coordinates have been optimized. The open-source code Critic2 was used to perform topological analyses. A detailed procedure for the evaluation of 𝛸(𝒓) using BAND is provided in the Supporting Information.