Orbital parity
= Orbital parity
{title2=$(-1)^\ell$}
An <orbital angular momentum> eigenstate with quantum number $\ell$ changes by the factor $(-1)^\ell$ under <spatial reflection>. Equivalently,
$$
Y_\ell^m(-\widehat{\mathbf r})=(-1)^\ell Y_\ell^m(\widehat{\mathbf r}).
$$