The <trigonal pyramidal molecular geometry> has \b[<C3v point group> symmetry]: identity, two rotations about the threefold axis, and three vertical mirror reflections. Choose $z$ along the threefold axis through <nitrogen> and the center of the hydrogen triangle.

Solution

Past exam of the chemistry A course of the University of Cambridge / 2021 / Paper 1 / A4 / a / i / Solution

 Solution (source code)