Computational Methods in Computational Chemistry

Computational chemistry provides theoretical tools to study molecular structures, energies, and properties using different levels of approximation. Molecular Mechanics (MM) models molecules with classical force fields and is highly efficient for large systems and long-time simulations, although it cannot describe electronic effects or chemical reactions. Semi-empirical quantum mechanical methods simplify quantum calculations by using empirical parameters, offering faster computations with moderate accuracy for large molecules. Ab initio methods solve the Schrödinger equation from first principles and provide high accuracy but at a high computational cost, limiting their application to small systems. Density Functional Theory (DFT) describes electronic systems based on electron density and offers an optimal balance between accuracy and efficiency for many chemical problems, although its reliability depends on the choice of exchange–correlation functional. The selection of a computational method depends on the research objective, system size, and required accuracy