 Hello, my name is G. Nuresh Patwari. I am from the Department of Chemistry IIT, Bombay. I will be teaching quantum mechanics and molecular spectroscopy scores through NPTEL platform. You could reach me at Nuresh at chem.itb.ac.in or g.nuresh.patwari.gmail.com. Apart from me, this course will have two teaching assistants, Ms. Namita Brigitte Bichoy who can be reached at Namita Brigitte at gmail.com and Ms. Sumitra Singh, Sumitra Singh 141 to at gmail.com. Essentially, this course deals with applications of quantum mechanics to molecular spectroscopy. The contents of this course are as follows. We will begin with simple introduction to quantum mechanics and look at the Schrodinger equation. Following which, we will develop time dependent perturbation theory and the time dependent perturbation in our case would be the interaction of light with matter. In such case, we will look at the classical properties of the light. In this case of course, we will use classical approach to the light and the interaction Hamiltonian that will be which will be the interaction between the light and molecule will be at a semi-classical level. Following which, we will evaluate transient probabilities and connect these transient probabilities to Einstein's A and B coefficients and also to a quantity called extinction coefficient which can be experimentally measured. Further, we will also look at spectral line shapes and lifetimes which can be both evaluated experimentally and theoretically and we will see the connection between the theory and the experiment. Finally, we will also derive the selection rules for rotational vibration and electronic transitions. For this course, I will assume some basic knowledge of quantum mechanics. Also, there is some exposure to mathematics students should be knowing about matrices, calculus and differential equations to some degree. Apart from that, if you have some exposure to group theory that would be good, but it is not necessary. Knowing group theory would be of a slightly advantageous position and the test books that I will recommend for this course are Molecular Quantum Mechanics by Atkins and Friedman, Molecular Spectroscopy by Gene McKair and Molecular Spectroscopy by Jack Grebel. I look forward to teaching this course to you on the NPTEL platform. Thank you.