DFT calculations on quetiapine hemifumarate as a pharmaceutical compound for the treatment of schizophrenia

In this work, the optimization calculations were carried out on quetiapine hemifumarat, 4, and its analogues, using B3LYP/6-31G(d) level of theory. The DFT calculations clarified a boat structure for dibenzothiazepine moiety of the molecule in which piperazine moiety has a chair conformation. Thermal energies (E), enthalpies (H), and Gibbs free energies (G) of quetiapine and its analogues, were calculated at the B3LYP/6-31G(d) level. The chemical hardness (?), chemical potential (?), dipole moment (D), electrophilicity (?) and the maximum amount of electronic charge, ?Nmax, were determined.