diff --git a/src/Methods/HartreeFock/UHF/UHFHelper.jl b/src/Methods/HartreeFock/UHF/UHFHelper.jl
index 90e95ff..b471d0f 100644
--- a/src/Methods/HartreeFock/UHF/UHFHelper.jl
+++ b/src/Methods/HartreeFock/UHF/UHFHelper.jl
@@ -198,4 +198,14 @@ function odadamping(D, Ds, F, Fs)
     damp = 1-λ
     F .= Fs
     return damp
-end
\ No newline at end of file
+end
+
+function UHFSpin(Nα , Nβ, Cα, Cβ, S)
+    # Calculate S^2 
+    smo=transpose(Cα)*S*Cβ
+    sz=0.25*(Nα-Nβ)^2
+    smo2=smo.^2
+    sxy=0.5*(Nα+Nβ)-sum(smo2[1:Nα,1:Nβ])
+    spinsquare=sz+sxy
+    return(spinsquare)
+end
diff --git a/src/Methods/HartreeFock/UHF/UHFa.jl b/src/Methods/HartreeFock/UHF/UHFa.jl
index 46a1262..52b9b18 100644
--- a/src/Methods/HartreeFock/UHF/UHFa.jl
+++ b/src/Methods/HartreeFock/UHF/UHFa.jl
@@ -161,9 +161,11 @@ function UHF(ints::IntegralHelper{Float64, <:AbstractERI, AtomicOrbitals}, Cα::
 
     nocc = Nα + Nβ  # TODO
     nvir = 2*m - nocc   #    output(repeat("-",80))
+    spinsquare=UHFSpin(Nα , Nβ, Cα, Cβ, S)
 
     output("    UHF done in {:>5.2f}s", t)
     output("    @Final UHF Energy     {:>20.12f} Eₕ", E)
+    output("    <S^2> = {:> 15.10f}",spinsquare)
     output("\n   • Orbitals Summary",)
     output("\n   ⬗ Alpha (α) orbitals")
     output("\n {:>10}   {:>15}   {:>10}", "Orbital", "Energy", "Occupancy")