https://www.efunda.com/glossary/units/units--electric_quadrupole_moment--au_of_electric_quadrupole_moment.cfm
eFunda: Glossary: Units: Electric Quadrupole Moment: A.u. of Electric Quadrupole Moment
eFunda: Glossary: Units: Electric Quadrupole Moment: A.u. of Electric Quadrupole Moment
electric quadrupole momentglossaryunits