Vol 3 - Landau, Lifshitz - Quantum mechanics - non-relativistic theory (3ed., 1991) · Problem 75.2

The Atom

Physics — Landau & Lifshitz · quadrupole-moment-electron

Problem

Express the quadrupole moment of an electron (charge

-|e|

) with orbital angular momentum

l

in terms of the mean square of its distance from the centre.