Written by a highly experienced author, this book fills the need for an accessible approach to grasping and working with the concepts of quantum theory. This is made possible by the use of MATLAB codes that allow the reader to experiment with the numerical techniques described. The book is also unique in its complete coverage of such hot topics as clusters, nanocrystals, transitions and organic molecules, while illustrating the DFT, the variational and various other methods, as well as approximate wave functions.