DFT Study on Ground State Electronic Structures of Simple to Complex Molecular Specimens

Abstract

As the first principles method involves quantum mechanical calculations derived directly from theoretical principles, their inabilities to solve the Schrödinger equation exactly for multi-electron systems make themselves far from fail-safe. To overcome the obstacles of exact computation, a more realistic Density Functional Theory (DFT) method of obtaining an approximate solution to the Schrödinger equation of a many-body system has become very prominent in the recent decades. Present work is aimed at computing ground state electronic structures of very simple to quite complex molecular specimens of the order: Water, Butadiene, Benzene, 1,4-bis (Tri-methylsilyl) Benzene, and Siloxaalkane by using DFT method and further strengthening its existing geometry optimization skills. At first, the isolated molecules of each of these specimens are fully optimized, and measured the dimensions of the particular sets of bond lengths, bond angles, and torsional angles in each ground state geometry. The theoretically computed values are found to be consistent with the concerned experimental values derived from the most advanced instrumentation techniques. It would be a strong evidence to support DFT method for being a very versatile and superb quantum mechanical model especially in computing ground state electronic structures of the complex molecular systems. The significance and novelty of this study lies in providing insight about the DFT predicted structural parameters and geometrical shapes of the aforementioned simple to complex molecular specimens.