Symmetry

This chapter examines how molecules possess certain symmetry elements, and each symmetry element gives rise to one or more symmetry operations. A symmetry operation, when applied to a molecule, leaves it in an identical position. The possible symmetry elements include axis of symmetry, mirror plane, centre of symmetry, and improper rotation axis. Symmetry considerations can be used to identify which atoms in a molecule are equivalent; determine whether or not a molecule has a dipole; and determine whether or not a molecule is chiral. Ultimately, orbitals can be classified as being symmetric or anti-symmetric with respect to the symmetry operations possessed by the molecule.