Phydical Chemiatry I Chapter IV Molecular Symmetry and Poirmt Group 2. Proper Axes and Proper Rotations C An n-fold rotation is symbolized by the element Cn, and represents n-1 rotational operations about the axis 20218/21 Chemistry Departme nt of Fudan UniversityPhysical ChemistryI Chemistry Department of Fudan University Chapter IV Molecular Symmetry and Point Group 2021/8/21 10 2. Proper Axes and Proper Rotations Cn An n-fold rotation is symbolized by the element Cn , and represents n–1 rotational operations about the axis. m Cn