As a part of the course CH504, Prof. E.D. Jemmis, IISc. Bangalore, will be giving three lectures scheduled on 26th March, 2nd and 5th April 2019 at 5.30 PM. Students learn electronic structure theory during the course work and from textbooks. They also learn to do computations using several software on molecules of interest. Most of the time computations reproduce experimental results and also can predict chemistry. Often the question of why the results support a particular possibility and not another is not obvious. Output of a program does not give this information directly. It is also true of experiments. If the results are not obvious, an understanding of why an experiment or a computation gives a particular result is needed. A beginning in this direction is attempted by these three lectures on qualitative MO theory. The lectures will be at an elementary level. Anyone interested in attending these lectures are welcome.