Chapter 11, Problem 11F.3DQ

Interpretation Introduction

Interpretation:

An explanation as to how the head bands in P and R branches arise has to be stated. Whether the Q branch shows a head or not is to be stated.

Concept introduction:

An electronic state of energy has its own vibrational states.  The energy between the electronic states is large followed by vibrational states and then rotational states.  During an electronic transition, electron from ground state moves straight to the excited state keeping the internuclear distance constant.  This is known as the Franck-Condon principle.