As of Version 9.0, unit functionality is built into the Wolfram Language

is a unit of energy.


  • To use , you first need to load the Units Package using Needs["Units`"].
  • is equivalent to approximately 2.1799×10-18 Joule (SI units).
  • is equivalent to approximately 2.1799×10-11 Erg.
  • Convert[n Rydberg,newunits] converts n Rydberg to a form involving units newunits.
  • is typically abbreviated as Ry.