diff --git a/ho_basis.jl b/ho_basis.jl
index 5746fc6..4a31c96 100644
--- a/ho_basis.jl
+++ b/ho_basis.jl
@@ -1,24 +1,24 @@
 # Gaussian potentials in HO space
-gl(R, l, k) = throw("unimplemented")
+gl(R, l, n) = throw("unimplemented")
 
-function get_sp_basis(max_N)
+function get_sp_basis(E_max)
+    ns = Int[]
     ls = Int[]
-    ks = Int[]
 
-    # Heyde p67
-    for N in max_N:-1:0
-        for l in N:-2:0
-            k = (N - l) / 2
+    # Heyde p67 with E = N and n = k + 1
+    for E in E_max:-1:0
+        for l in E:-2:0
+            n = 1 + (E - l) / 2
+            push!(ns, n)
             push!(ls, l)
-            push!(ks, k)
         end
     end
 
-    return (ls, ks)
+    return (ns, ls)
 end
 
-get_V_matrix(V_lk, ls, ks) = throw("unimplemented")
+get_V_matrix(V_l, ls, ns) = throw("unimplemented")
 
-get_T_matrix(ls, ks) = throw("unimplemented")
+get_T_matrix(ns, ls) = throw("unimplemented")
 
-get_H_matrix(V_ls, ls, ks) = get_T_matrix(ls, ks) + get_V_matrix(V_lk, ls, ks)
+get_H_matrix(V_l, ns, ls) = get_T_matrix(ns, ls) + get_V_matrix(V_l, ns, ls)