Using calcium's simple cubic (sc) phase, this study emphasizes the potential role of quantum crystallography (QCr) in enhancing our understanding of high-pressure electrides (HPEs). The electronegativity of an atom, or the topology of the crystalline electron density, are features that can be calculated using quantum mechanical methods as well as measured and quantified experimentally. By modelling the electronic structure of calcium under pressure with the r 2 SCAN functional, we have performed a series of theoretical experiments to show the numerous chemical and physical information that can be unlocked by QCr. Utilizing advanced topological analyses of the electron density, we obtained results that support the HPE nature of Ca-sc and it's formation through the multi-center bonding (MCB) model via the hybridization of spd-orbitals, which has been proposed in past works . Our results also confirm that the emergence of the HPE state is closely tied to the emergence of orbital hybridization and stabilization of the d-states under pressure. Moreover, we have performed the very first theoretical survey of the electronegativity evolution of an element upon several high-pressure phase transitions in the solid state, which can be probed experimentally using spectroscopic techniques. This survey highlighted an unexpected jump in the electronegativity of calcium upon transition to the sc-phase, which could become an additional signature for detecting the formation of the electride state. The application of QCr methodologies in this computational study serves as a bridging framework between theoretical predictions with the potential experimental validation for understanding the electronic structure and bonding attitudes of HPEs. These findings lay a solid foundation for future experimental endeavors aimed at characterizing and confirming these elusive high-pressure phases, ultimately enriching our understanding of complex materials under extreme conditions.