AB Initio investigations of structural electronic and optical properties for useful molecules

Abstract

Quantum mechanics provides the mathematical description of the behavior of electrons in the molecules In the last few decades a new area of research interest which is governed by the laws of quantum mechanics has emerged It is known as molecular quantum mechanics and became an interdisciplinary subject that straddles physics chemistry and biology It is prominently used to explore the behaviour of variety of chemical and biological systems of interest at the atomic and molecular level It helps us to understand the fundamental features of the molecules such as structure bonding between the atoms inter and intra molecular forces stability and material properties such as charge transport biological and chemical activity optical and electronic behaviour A complete knowledge on the properties of the atoms and molecules is necessary to design new materials with improved properties for required applications. Limitations that computational tools had in the past which led to faulty conclusions have been overcome in recent years Now a days new research problems in different areas of chemistry can be supported and properly guided by making use of available computational techniques. Moreover quantum chemical techniques can help resolve issues that cannot be practically achieved due to instrumentation limits. Computational chemistry especially highlevel theories and calculations specially Hartree-Fock and Density functional Theory can also help refine and perhaps change some of the old concepts and understanding of chemical phenomena newlineThe vibrational spectroscopy coupled with quantum mechanical calculations can be a powerful method for understanding the structural conformational vibrational and electronic behavior of molecules. Electronic correlation to the calculations is necessary to get more reliable results on the structural parameters physiochemical properties and vibrational properties Among many leading factors electron delocalization is a very common effect which influences the characteristic of molecules