1 Preface 2 Introduction I Basics of group theory 3 Symmetry operations and transformations of fields 4 Basic abstract group theory 5 Discrete symmetry groups for solid state physics and photonics 6 Representation theory 7 Symmetry in k-space II Applications in electronic structure theory 8 Solution of the Schroedinger equation 9 Generalization to include the spin 10 Electronic energy bands III Applications in photonics 11 Solution of Maxwell's equations 12 Twodimensional photonic crystals 13 Threedimensional photonic crystals 14 Other Applications A Mathematica Package Reference B Connection of the group theory package to MPB and MEEP sakriti opis