The optimized geometry, H-1 and C-13 NMR chemical shifts, conformational and natural bond orbital (NBO) analyses, thermodynamic parameters, molecular surfaces, Mulliken, NBO and APT charges for 5-(2-Chloroethyl)-2,4-dichloro-6-methylpyrimidine [C7H7C13N21 were investigated by the ab initio HF and density functional theory (DFT/B3LYP) methods with 6-311++G(d,p) basis set. The calculated structural parameters (bond lengths, bond angles and dihedral angles) and H-1 and C-13 NMR chemical shifts values are compared with experimental values of the investigated compound. The observed and the calculated values are found to be in good agreement. The energies of the highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) were calculated, and the obtained energies displayed that charge transfer occurs in 5-(2-Chloroethyl)-2,4-dichloro-6-methylpyrimidine compound. In addition, the linear polarizability (alpha) and the first order hyperpolarizability (beta ) values of the investigated compound have been computed by using HF and DFT methods. (c) 2014 Elsevier B.V. All rights reserved.