diff --git a/contents/quantum_systems/code/julia/energy.jl b/contents/quantum_systems/code/julia/energy.jl
index d045d073c..3efce0cb7 100644
--- a/contents/quantum_systems/code/julia/energy.jl
+++ b/contents/quantum_systems/code/julia/energy.jl
@@ -1,12 +1,12 @@
 # We are calculating the energy to check <Psi|H|Psi>
 function calculate_energy(wfc, H_k, H_r, dx)
     # Creating momentum and conjugate wavefunctions
-    wfc_k = fft(wfc_r)
-    wfc_c = conj(wfc_r)
+    wfc_k = fft(wfc)
+    wfc_c = conj(wfc)
 
     # Finding the momentum and real-space energy terms
     energy_k = wfc_c.*ifft((H_k) .* wfc_k)
-    energy_r = wfc_c.* H_r .* wfc_r
+    energy_r = wfc_c.* H_r .* wfc
 
     # Integrating over all space
     energy_final = 0