"A Handbook of Density Functional Theory" serves as an accessible and comprehensive guide for absolute beginners venturing into the realm of theoretical chemistry and computational materials science. With clear explanations and practical examples, this book demystifies the fundamental concepts and techniques of Density Functional Theory (DFT), providing readers with the essential knowledge and skills needed to embark on their journey of understanding electronic structure calculations, molecular simulations, and material properties prediction. Whether you're a student, researcher, or enthusiast, this handbook offers a valuable resource to navigate the intricacies of DFT and unlock its potential in unraveling the mysteries of matter at the atomic and molecular level.