Symmetry (Physics) Group theory 12 Molecular theory 5 Molecular orbitals 4 Molecular structure 4 Mathematics 3 Chemistry 2 Chemistry, Physical and theoretical 2 Crystallography 2 Crystallography, Mathematical 2 Molecular spectroscopy 2 Particles (Nuclear physics) 2 Stereochemistry 2 Calculus of tensors 1 Calculus of variations 1 Chemical bonds 1 Chemical reaction, Conditions and laws of 1 Combinatorial analysis 1 Condensed matter 1 Conservation laws (Physics) 1 Coordination compounds 1 Crystals 1 Crystals- Structure 1 Differential equations, Partial 1 Electron spectroscopy 1 Functions, Special 1 Gauge fields (Physics) 1 Hadrons 1 Hamiltonian systems 1 Heterostructures 1