Update src/8_many_atoms_sol.md

src/8_many_atoms_sol.md

@@ -36,8 +36,8 @@ A unit cell consits of exactly one $t_1$ and exactly $t_2$ hopping.
 ### Subquestion 2
 
 Using the hint we find:
-$$ E \phi_0 = \epsilon \phi_0 + t_1 \psi_0 + t_2 \psi_{n-1} $$
-$$ E \psi_0 = \epsilon \psi_0 + t_2 \phi_{n+1} + t_2 \phi_0 $$
+$$ E \phi_0 = \epsilon \phi_0 + t_1 \psi_0 + t_2 \psi_0 e^{ika} $$
+$$ E \psi_0 = \epsilon \psi_0 + t_2 \phi_0 e^{-ika} + t_2 \phi_0 $$
 
 Notice that the hopping, in this case, is without the '-'-sign!