The term theoretical chemistry may be defined as the mathematical description of chemistry. The term computational chemistry is usually used when a mathematical method is sufficiently well developed that it can be automated for implementation on a computer.

Computational chemistry is a natural outgrowth of theoretical chemistry, the traditional role of which involves the establishment of a conceptual understanding and quantitative characterization for the chemical sciences, particularly at the atomic and molecular levels.

During the last few decades, an enormous development of user-friendly computational chemistry software that has made molecular calculations accessible to many users, so that molecular modeling can now be performed in any laboratory or classroom. The continuous rapid increase in the power of individual PCs is offering comparatively low-cost options to substitute expensive experimental studies.

Computational chemistry programs are used for:

• calculating the molecular properties such as structure of molecules, energy, dipole moment, electronic charge, and spectroscopic measurements and so on.
• performing simulation to macromolecular systems such as nucleic acids, lipids and proteins, or system of large number of molecules like gases, liquids and liquid crystals
• drug design, design of new catalysts, chemical synthesis, reaction mechanism studies, and design of novel materials.

Theoretical and Computational Chemistry is a fast growing area of modern chemistry. It is capable of interfacing with the other teaching and research areas in chemistry, physics, biochemistry, pharmaceutical chemistry, material science etc.   

Computational chemistry teaching and research is currently active in most countries, including developed and developing countries. However, computational chemistry teaching and research is not yet active in Bangladesh. Considering the significance of the study of Theoretical and Computational Chemistry in the 21^st century, the University of Dhaka authorities have created the Department of Theoretical and Computational Chemistry.

List of computational software currently available in the Department of Theoretical and Computational Chemistry:

1. Gaussian 16
2. GaussView 6
3. VASP