diff --git a/ho_basis.jl b/ho_basis.jl
index cc4ef02..00c3659 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 0 : E_max
+    for E in E_max : -2 : 0 # same parity states only
         for n1 in 0 : E ÷ 2
             for n2 in 0 : (E - 2*n1) ÷ 2
                 for l1 in 0 : (E - 2*n1 - 2*n2)
@@ -83,21 +83,17 @@ function sp_V_matrix(V_l, ns, ls; mask=trues(length(ns),length(ns)), dtype=Float
 end
 
 function Moshinsky_transform(Es, n1s, l1s, n2s, l2s, Λ)
-    Emax = maximum(Es)
+    NQMAX = maximum(Es)
+    @assert all(mod.(Es, 2) .== mod(NQMAX, 2)) "Can only admit basis states with same parity"
 
     LMIN = Λ
     LMAX = Λ
     CO = 1/sqrt(2)
     SI = 1/sqrt(2)
 
-    BRACs = Vector{Array{Float64}}(undef, 2) # two arrays for both parities
-
-    for parity in 1:2
-        NQMAX = Emax - mod1(Emax, 2) + parity
-        # dimensions BRAC(0:LMAX,0:(NQMAX-LMIN)/2,0:(NQMAX-LMIN)/2,0:(NQMAX-LMIN)/2,0:(NQMAX-LMIN)/2,0:LMAX,0:(NQMAX-LMIN)/2,LMIN:LMAX)
-        BRACs[parity] = zeros(Float64, 1 + LMAX, 1 + (NQMAX - LMIN) ÷ 2, 1 + (NQMAX - LMIN) ÷ 2, 1 + (NQMAX - LMIN) ÷ 2, 1 + (NQMAX - LMIN) ÷ 2, 1 + LMAX, 1 + (NQMAX-LMIN) ÷ 2, 1 + LMAX-LMIN)
-        @ccall "../OSBRACKETS/allosbrac.so".allosbrac_(NQMAX::Ref{Int32},LMIN::Ref{Int32},LMAX::Ref{Int32},CO::Ref{Float64},SI::Ref{Float64},BRACs[parity]::Ptr{Array{Float64}})::Cvoid
-    end
+    # dimensions BRAC(0:LMAX,0:(NQMAX-LMIN)/2,0:(NQMAX-LMIN)/2,0:(NQMAX-LMIN)/2,0:(NQMAX-LMIN)/2,0:LMAX,0:(NQMAX-LMIN)/2,LMIN:LMAX)
+    BRAC = zeros(Float64, 1 + LMAX, 1 + (NQMAX - LMIN) ÷ 2, 1 + (NQMAX - LMIN) ÷ 2, 1 + (NQMAX - LMIN) ÷ 2, 1 + (NQMAX - LMIN) ÷ 2, 1 + LMAX, 1 + (NQMAX-LMIN) ÷ 2, 1 + LMAX-LMIN)
+    @ccall "../OSBRACKETS/allosbrac.so".allosbrac_(NQMAX::Ref{Int32},LMIN::Ref{Int32},LMAX::Ref{Int32},CO::Ref{Float64},SI::Ref{Float64},BRAC::Ptr{Array{Float64}})::Cvoid
     
     mat = zeros(length(Es), length(Es))
 
@@ -107,8 +103,7 @@ function Moshinsky_transform(Es, n1s, l1s, n2s, l2s, Λ)
         (Elhs, N, L, n, l) = s[i, :]
         (Erhs, n1, l1, n2, l2) = s[j, :]
         if Elhs == Erhs && triangle_ineq(L, l, Λ) && triangle_ineq(l1, l2, Λ)
-            parity = mod1(Elhs, 2)
-            mat[i, j] = (-1)^(n1 + n2 + N + n) * pick_Moshinsky_brakcet(BRACs[parity], n1, l1, n2, l2, N, L, n, l, Λ)
+            mat[i, j] = (-1)^(n1 + n2 + N + n) * pick_Moshinsky_brakcet(BRAC, n1, l1, n2, l2, N, L, n, l, Λ)
         end
     end