Using the Extended-Rydberg Function to Study Some of Spectral Properties of Some Molecules

In this work, (Extended-Rydberg function) has been used to determine the values of the energy and the form of the energy curve and some Spectral characteristics of some Germanium-Tetrahalides (GeBr4 and GeI4) by depending on dissociation energy, bond length at equilibrium and by changing bond lengths between (Ge-Br), (Ge-I). Our calculation has been done using semi-empirical quantum programs (PC Model, Winmopac7.21, and Hyperchem ) with MNDO/PM3 method which takes a short period of time comparing with (ab-initio). The spectral properties as modes, vibration frequencies, intensities and Symmetry have been calculated for each mode at equilibrium. Also, the total energy, dipole moment, zero point energy and molecular weight have been calculated by Winmopac 7.21 program. Also, HOMO energy, LUMO energy, ionization potential and electron affinity have been determined in the results.