Vibrational, electronic, spectroscopic properties, and NBO analysis of p-xylene, 3,6-difluoro-p-xylene, 3,6-dichloro-p-xylene and 3,6-dibromo-pxylene: DFT study.

This study explains the vibration and interaction of p-xylene and effect of three elements (fluorine, chlorine and bromine) of the halogen family substitution on it. Basic chemistry of four, compounds p-xylene (PX); 3,6-diflouro-p-xylene (DFPX); 3,6-dichloro-p-xylene (DCPX) and 3,6-dibromo-p-xylene (DBPX) has been explained extensively using theoretical approach. Vibrational energy distribution analysis (VEDA) software was used to study the potential energy distribution (PED) analysis, bond length, bond angles and dihedral angles of PX, DFPX, DCPX, DBPX after optimization with GAUSSIAN 09 software.

Evaluation of the bound state energies of some diatomic molecules from the approximate solutions of the Schrodinger equation with Eckart plus inversely quadratic Yukawa potential.

We have obtained analytically the bound state solutions for the non-relativistic Schrodinger equation for the Eckart plus inversely quadratic Yukawa potential (EIQYP) using the parametric Nikiforov-Uvarov (NU) method. In order to validate our approximation, the bound state energies were computed and predicted for some selected diatomic molecules at different adjustable screening parameters from the available spectroscopic model parameters. The fact-finding obtained are in agreement with previously reported results available in literature.