Molecules

This course begins with a brief overview of molecular physics. I will review the solutions to the Schrödinger equation for the hydrom atom and then use the hydrogen wavefunctions to describe multi-electron atoms. Molecules are ussually described either in terms of valence bond theory where the solutions are constructed from hydrogen wavefunctions or molecular orbital theory where orbitals for a single electron are calculated and then these are used to construct a multi-electron wavefunction.

Reading
Review the hydrogen atom: Demtröder - Das Wasserstoffatom
Read the section of this chapter on Helium: Demtröder - Atome mit mehreren Elektronen
Read the chapter on molecules: Demtröder - Moleküle

    For the exam you should
  • Be familar with the hydrogen wave functions
  • Be able to construct the multi-electron wave functions of any atom as antisymmetrized products of hydrogen wave functions
  • Be able to write down the total Hamiltonian for any molecule
  • Be able to evaluate the energy of a trial wavefunction (a guess) in any Hamiltonian
  • Be able to write down the electronic Hamiltonian of any molecule in the Born-Oppenheimer approximation
  • By neglecting the electron-electron interactions in the electronic Hamiltonian, you should be able to solve it by the separation of variables and construct the molecular orbital Hamiltonian
  • You should know how to solve the molecular orbital Hamiltonian using a Linear Combination of Atomic Orbitals (LCAO)
  • Explain Hückel theory
  • Be able to construct a multi-electron molecular wavefunction as an antisymmetrized product of molecular orbitals
  • Be able to use valence bond theory to calculate a bond potential such as the Morse potential or the Lennard-Jones potential
  • Be able to determine the vibrational states of a bond from the bond potential
  • Be able to calculate the rotational states of molecules
  • Be familar with the solutions to the Schrödinger equation for a particle in an infinite square well and a particle confined to a ring
  • Be able to define: single bond, double bond, triple bond, polar bond, covalent bond, π-bond, σ-bond, metallic bond, ionic bond, valence bond theory, molecular orbital theory, sp orbital, sp² orbital, sp³ orbital, bonding orbital, antibonding orbital, singlet state, triplet state

Resources
Handbook of Basic Atomic Spectroscopic Data (NIST)
Molecular Spectral Databases (NIST)