Molecular spectroscopy and structure

Course details

Course lecturers:
Dr Colin Western (CMW)

Date: Autumn 2009
See also: Wikipedia notes on this course

Table of contents

  1. Textbooks
    1. Texts recommended by the lecturers
    2. Other coverage
  2. Diatomic Molecules
    1. Molecular orbital diagram; Term Symbols; Selection Rules
    2. Separation of motions
  3. Rotation
    1. Energy levels of linear molecules
    2. Moments of inertia; determining geometry from rotational constants
    3. Non-linear molecules; symmetric and asymmetric tops
    4. Microwave spectroscopy; application to astronomy
  4. Electronic States
    1. Term symbols for polyatomic molecules
    2. Change of orbital energy with geometry - Walsh diagrams for H2O, NH3 and C2H4 (π orbitals)
    3. Consequences for electronic and photoelectron spectrum
    4. Selection rules. Rovibronic Spectra
  5. Characteristics of Electronic Transitions
    1. Transition strength/dipole; Forbidden transitions
    2. Types of transitions and chromophores: d–d; charge transfer; π−π*, n−π*
  6. Vibration
    1. Potential energy curves and Franck-Condon factors; Photoelectron spectroscopy
    2. Normal modes and symmetry. Infrared active and inactive modes. Force constants.
    3. Degenerate modes


Texts recommended by the lecturers

  • Modern Spectroscopy (4th edition)
    J. M. Hollas
    Wiley (2003)
    ISBN 978-0-470-84416-8 (Wiley,

  • High Resolution Spectroscopy (2nd edition)
    J. M. Hollas
    Wiley (1998)
    ISBN 978-0-471-97421-5 (Wiley,

Other coverage

Diatomic Molecules

Coming soon!