Document Type : Original Article
Authors
1
Nano Technology Unit, Space Lab, Solar and Space Research Department, National Research Institute of Astronomy and Geophysics (Nano NRIAG), Helwan, Cairo, Egypt
2
Physics Department, Faculty of Women for Arts, Science and Education, Ain Shams University, 11757 Cairo, Egypt.
3
Molecular Spectroscopy and Modeling Unit, Spectroscopy Department, National Research Centre, 33 El-Bohouth Str. 12622 Dokki, Giza, Egypt
4
Synchrotron-Light for Experimental Science and Applications in the Middle East (SESAME), Allan, JORDAN.
Abstract
Molecular modeling is considered as an effective tool for the evaluation of many physical as well as spectroscopic parameters. In this study semiempirical AM1, PM5, ab initio methods HF and MP2 as well as density functional methods VWN, B88LYP, B88PW91, B3PW91 and B3LYP were used to study nitromethane in its gas phase. The optimized structure, some physical parameters, and vibrational spectrum were calculated and discussed. The calculated optimized structure indicated that nitromethane (NM) belongs to the point group C2V. The obtained data indicated that quantum mixing gives results comparable to both ab initio method in accuracy and semiempirical method in computation time. It is concluded that for a small structure like NM, quantum mixing method provides reliable results in a short computation time. At B3LYP/6-31G(d,p) level, polar solvents showed changes in both HOMO/LUMO band gap energy and molecular electrostatic potential. This is an indication for the stability of NM in different chemical environments.
Keywords
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