diff --git a/ho_basis.jl b/ho_basis.jl
index 2c802f0..44c8427 100644
--- a/ho_basis.jl
+++ b/ho_basis.jl
@@ -35,7 +35,7 @@ function get_2p_basis(E_max)
     l2s = Int[]
 
     # E = 2*n1 + l1 + 2*n2 + l2
-    for E in 2*E_max : -2 : 0
+    for E in 0 : 2 * E_max
         for n1 in 0 : E ÷ 2
             for n2 in 0 : (E - 2*n1) ÷ 2
                 for l1 in 0 : (E - 2*n1 - 2*n2)