diff --git a/src/det.irp.f b/src/det.irp.f
index 07a4b52..967cc7f 100644
--- a/src/det.irp.f
+++ b/src/det.irp.f
@@ -100,14 +100,7 @@ BEGIN_PROVIDER [ integer*1, det_exc, (det_num, det_num, 2) ]
      endif
     enddo
     det_exc(k,l,p) *= (1-2*mod( nperm, 2 ))
-   enddo
-  enddo
- enddo
-
- do p=1,2
-  do l=1,det_num
-   do k=1,l-1
-    det_exc(k,l,p) = det_exc(l,k,p)
+    det_exc(l,k,p) = det_exc(k,l,p)
    enddo
   enddo
  enddo
diff --git a/src/eplf_function.irp.f b/src/eplf_function.irp.f
index d756c7a..c3df9d1 100644
--- a/src/eplf_function.irp.f
+++ b/src/eplf_function.irp.f
@@ -123,46 +123,38 @@ END_PROVIDER
      nact  = elec_num_2(p) -mo_closed_num
      nact2 = elec_num_2(p2)-mo_closed_num
      if ( exc(3) == 0 ) then
-      ! Closed-open shell interactions
-      do j=1,mo_closed_num
-       do n=1,nact
-        ik = det(n,k,p)
-        il = det(n,l,p)
-        dtemp(1) += (  &
-           mo_value_prod_p(il,ik)*mo_eplf_integral_matrix(j,j) - &
-           mo_value_prod_p(j,ik)*mo_eplf_integral_matrix(j,il) )
-        dtemp(2) += mo_value_prod_p(il,ik)*mo_eplf_integral_matrix(j,j) 
-       enddo
-      enddo
+      do n=1,nact
+       jk = det(n,k,p)
+       jl = det(n,l,p)
 
-      !- Open-closed shell interactions
-      do m=1,nact
-       jk = det(m,k,p)
-       jl = det(m,l,p)
        do i=1,mo_closed_num
-         dtemp(1) += (  &
+        ! Closed-open shell interactions
+        dtemp(1) += (  &
+           mo_value_prod_p(jl,jk)*mo_eplf_integral_matrix(i,i) - &
+           mo_value_prod_p(i,jk)*mo_eplf_integral_matrix(i,jl) )
+        dtemp(2) += mo_value_prod_p(jl,jk)*mo_eplf_integral_matrix(i,i) 
+
+        !- Open-closed shell interactions
+        dtemp(1) += (  &
            mo_value_prod_p(i,i)*mo_eplf_integral_matrix(jl,jk) - &
            mo_value_prod_p(i,jl)*mo_eplf_integral_matrix(i,jk) )  
-         dtemp(2) += mo_value_prod_p(i,i)*mo_eplf_integral_matrix(jl,jk) 
+        dtemp(2) += mo_value_prod_p(i,i)*mo_eplf_integral_matrix(jl,jk) 
        enddo
-      enddo
 
-      !- Open-open shell interactions
-      do m=1,nact
-       jk = det(m,k,p)
-       jl = det(m,l,p)
-       do n=1,nact
-         ik = det(n,k,p)
-         il = det(n,l,p)
+       !- Open-open shell interactions
+       do m=1,nact
+         ik = det(m,k,p)
+         il = det(m,l,p)
          dtemp(1) += (  &
            mo_value_prod_p(il,ik)*mo_eplf_integral_matrix(jl,jk) - &
            mo_value_prod_p(jl,ik)*mo_eplf_integral_matrix(il,jk) )
        enddo
-       do n=1,nact2
-         ik = det(n,k,p2)
-         il = det(n,l,p2)
+       do m=1,nact2
+         ik = det(m,k,p2)
+         il = det(m,l,p2)
          dtemp(2) += mo_value_prod_p(ik,il)*mo_eplf_integral_matrix(jl,jk) 
        enddo
+
       enddo
  
      else if ( (exc(3) == 1).and.(exc(p) == 1) ) then
@@ -170,16 +162,14 @@ END_PROVIDER
      ! Sum over only the sigma-sigma interactions involving the excitation
       call get_single_excitation(k,l,ik,il,p)
 
-      !- Open-closed shell interactions
-      do j=1,mo_closed_num
-       dtemp(1) += (  &
-           mo_value_prod_p(il,ik)*mo_eplf_integral_matrix(j,j) - &
-           mo_value_prod_p(j,ik)*mo_eplf_integral_matrix(j,il) )
-       dtemp(2) += mo_value_prod_p(ik,il)*mo_eplf_integral_matrix(j,j)
-      enddo
-
-      !- Closed-open shell interactions
       do i=1,mo_closed_num
+       !- Open-closed shell interactions
+       dtemp(1) += (  &
+           mo_value_prod_p(il,ik)*mo_eplf_integral_matrix(i,i) - &
+           mo_value_prod_p(i,ik)*mo_eplf_integral_matrix(i,il) )
+       dtemp(2) += mo_value_prod_p(ik,il)*mo_eplf_integral_matrix(i,i)
+
+       !- Closed-open shell interactions
        dtemp(1) += (  &
            mo_value_prod_p(i,i)*mo_eplf_integral_matrix(jl,jk) - &
            mo_value_prod_p(i,jl)*mo_eplf_integral_matrix(i,jk) )