Update 5_atoms_and_lcao_solutions.md - typo

docs/5_atoms_and_lcao_solutions.md

@@ -116,4 +116,4 @@ We find the polarization using
 $$
 P=2e\langle\psi|\hat{x}|\psi\rangle = 2e\left(\phi_1^2\langle 1|\hat{x}| 1 \rangle + \phi_2^2\langle 2|\hat{x}| 2 \rangle \right) = ed(\phi_2^2-\phi_1^2) =ed\frac{\eta}{1-\eta}
 $$
-Does the answer make sense for $eta=0$?
+Does the answer make sense for $\eta=0$?