Scientific publications
Geh Wilson Ejuh
Amar Singh
The African review of physics
Molecular modeling of the structure of Pyrimethamine molecule has been carried out in an attempt to un derstand its structure and thermo-dynamical properties using the Hessian matrix. Ab initio and DFT geometric optimizations were carried out at RHF/6-311++G** and B3Lyp/6-311++G** level of theory in the gas medium. The zero point vibrationa l energy (ZPVE), enthalpy (H), entropy (S) and relative free energy (G) have been calculated from the frequenci es obtained by an analytical Hessian calculation. The polarizability tensor components, the average polarizability and t he anisotropy have also been calculated. The theoretical calculation shows that B3LYP/6-311++G** values were higher than the RHF/6-311, a result we believe is due to the effect of electron correla tion.
