ChemistryAngular momentumUniversity

Angular momentum operator Calculator

Defines orbital angular momentum as the cross product of position and momentum operators.

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Overview

This operator measures rotational motion and generates the angular quantum numbers used in atomic orbitals and rigid rotors.

Apply it well

When To Use

When to use: Defines orbital angular momentum as the cross product of position and momentum operators.

Why it matters: This operator measures rotational motion and generates the angular quantum numbers used in atomic orbitals and rigid rotors.

Avoid these traps

Common Mistakes

  • Treating L as ordinary scalar momentum.
  • Forgetting that components of L do not all commute.

One free problem

Practice Problem

What two operators are crossed to form orbital angular momentum?

Solve for: $\hat{\mathbf{L}}

Hint: Focus on what the formula is telling you physically.

The full worked solution stays in the interactive walkthrough.

References

Sources

  1. Chemistry LibreTexts, Rotational Motions of Rigid Molecules; Chemistry LibreTexts, Selection Rule for the Rigid Rotator
  2. Chemistry LibreTexts, Rotational Motions of Rigid Molecules
  3. Chemistry LibreTexts, Selection Rule for the Rigid Rotator
  4. NIST CODATA
  5. IUPAC Gold Book
  6. Quantum Mechanics (Griffiths)
  7. Introduction to Quantum Mechanics (Liboff)
  8. Griffiths, David J. Introduction to Quantum Mechanics. 3rd ed., Cambridge University Press, 2018.