Atomic charges are derived from two dissimilar methods of partitioning the electron density of diatomic molecules. The results given by both methods are similar, with the exception of those for molecules containing lithium; factors responsible for this discrepancy are explored. The charges derived are correlated closely with electronegativity differences and with dipole moments. They follow chemically sensible trends and have reasonable magnitudes. The partitioning methods used in the derivation can also be applied to the analysis of diffraction data for crystalline solids.