1. Each orbital in an atom is characterized by a unique set of values of the three quantum numbers n, l, and m, which respectively correspond to the electron's energy, angular momentum, and an angular momentum vector component (the magnetic quantum number).

2. Other than principal quantum number (n), spectroscopic notation, magnetic quantum number (m) and the spin quantum number (s) – the Azimuthal quantum number is another set of quantum numbers which describe the unique quantum state of an electron. It can be defined as, The quantum number associated with the angular momentum of an atomic electron.