BEGIN_PROVIDER [ logical, initialize_pt2_E0_denominator ]
 implicit none
 BEGIN_DOC
 ! If true, initialize pt2_E0_denominator
 END_DOC
 initialize_pt2_E0_denominator = .True.
END_PROVIDER

BEGIN_PROVIDER [ double precision, pt2_E0_denominator, (N_states) ]
 implicit none
 BEGIN_DOC
 ! E0 in the denominator of the PT2
 END_DOC
 integer :: i,j
 if (initialize_pt2_E0_denominator) then
   if (h0_type == "EN") then
     pt2_E0_denominator(1:N_states) = psi_energy(1:N_states)
   else if (h0_type == "HF") then
     do i=1,N_states
       j = maxloc(abs(psi_coef(:,i)),1)
       pt2_E0_denominator(i) = psi_det_hii(j)
     enddo
   else if (h0_type == "Barycentric") then
     pt2_E0_denominator(1:N_states) = barycentric_electronic_energy(1:N_states)
   else if (h0_type == "CFG") then
     pt2_E0_denominator(1:N_states) = psi_energy(1:N_states)
   else
     print *,  h0_type, ' not implemented'
     stop
   endif
  do i=1,N_states
    call write_double(6,pt2_E0_denominator(i)+nuclear_repulsion, 'PT2 Energy denominator')
  enddo
 else
   pt2_E0_denominator = -huge(1.d0)
 endif
END_PROVIDER