Electron Properties of Carbamazepine Drug in Form III

Abstract

The experimental electron and electrostatic properties of carbamazepine drug molecule (form III) were determined from accurate high-resolution X-ray diffraction data collected at 100 K. The results are compared to quantum mechanics calculations for gas-phase molecule and multimers. The experimental electron density was refined using the Hansen–Coppens multipole formalism, and the deformation electron density maps are compared to the theoretical ones. Both experimental and theoretical deformation electron density maps presented here are based on Clementi’s promolecule densities used as a reference. The topological analysis of the carbamazepine electron density using Bader’s theory has been carried out, and the integrated atomic charges are presented and compared to those obtained for molecules with equivalent chemical fragments. The charge values compare qualitatively well with those obtained by theoretical calculations. The electrostatic potential features and the interaction electrostatic energies are also discussed.