diff --git a/devel/sr_correction/energy_mu.irp.f b/devel/sr_correction/energy_mu.irp.f
index 2f105d4..56da4ab 100644
--- a/devel/sr_correction/energy_mu.irp.f
+++ b/devel/sr_correction/energy_mu.irp.f
@@ -24,6 +24,7 @@ BEGIN_PROVIDER [ double precision, W_mu, (mo_num, mo_num, mo_num, mo_num) ]
  END_DOC
 
  integer :: i,j,k,l
+ integer :: ii,jj,kk,ll
  do l=1,mo_num
    do k=1,mo_num
      do j=1,mo_num
@@ -34,6 +35,14 @@ BEGIN_PROVIDER [ double precision, W_mu, (mo_num, mo_num, mo_num, mo_num) ]
      enddo
    enddo
  enddo
+
+ do ii=1,n_core_orb
+   i = list_core(ii)
+   W_mu(i,:,:,:) = W_bar_mu0(i,:,:,:)
+   W_mu(:,i,:,:) = W_bar_mu0(:,i,:,:)
+   W_mu(:,:,i,:) = W_bar_mu0(:,:,i,:)
+   W_mu(:,:,:,i) = W_bar_mu0(:,:,:,i)
+ enddo
 END_PROVIDER
 
 BEGIN_PROVIDER [ double precision, W_bar_mu, (mo_num, mo_num, mo_num, mo_num) ]
@@ -47,8 +56,7 @@ BEGIN_PROVIDER [ double precision, W_bar_mu, (mo_num, mo_num, mo_num, mo_num) ]
    do k=1,mo_num
      do j=1,mo_num
        do i=1,mo_num
-         double precision, external :: mo_two_e_integral
-         W_bar_mu(i,j,k,l) = mo_two_e_integral(i,j,k,l) - W_mu(i,j,k,l)
+         W_bar_mu(i,j,k,l) = W_bar_mu0(i,j,k,l) - W_mu(i,j,k,l)
        enddo
      enddo
    enddo