The electronic structure of a wide range of apatite compounds Me-10(AsO4)(6)X-2, where Me = Ca and Cd, X = F, Cl, OH, and Br, has been calculated using first principles within the framework of density functional theory. This was achieved via the full-potential all-electron augment plane wave (APW) method with a set of basis functions with the addition of local orbitals (APW + lo). The study established the effects of changes in spatial charge distributions and the energy structure of valence and conduction bands for apatites in the specified series. Bader charge analysis was performed to clarify the nature of chemical bonding in apatite compounds of the Me-10(AsO4)(6)X-2 series, where Me = Ca and Cd, X = F, Cl, OH, and Br. Additionally, the unit cell parameters for apatites of the specified series were calculated.