The unit provides the basis for a solid understanding of the principles important to both chemists and physicists that determine fundamental atomic and molecular properties. Topics covered will be tailored for students considering either physics or chemistry and will be selected from the following: Symmetry and structure of molecules and crystals; Spectroscopy of atoms and molecules, including electronic, rotational and vibrational spectra, fluorescence and phosphorescence; the theory of quantum mechanics and its application to model systems including the simple harmonic oscillator and the hydrogenic atom, spin, identical particles and quantum statistics, and approximation methods. PHYS501 is based on the undergraduate unit with additional assessment and requires a greater level of understanding of the unit material.