function calc_pgen_mol_guga_single(ilutI, nI, csf_i, ilutJ, nJ, excitInfo) result(pgen)
integer(n_int), intent(in) :: ilutI(0:niftot), ilutJ(0:niftot)
integer, intent(in) :: nI(nel), nJ(nel)
type(CSF_Info_t), intent(in) :: csf_i
type(ExcitationInformation_t), intent(in) :: excitInfo
real(dp) :: pgen
real(dp) :: p_orbs, p_guga
! write a pgen calculator for guga-excitations finally..
! but only for the molecular for now!
! i need the orbital picking part of pgen:
p_orbs = calc_pgen_mol_guga_single_orbs(ilutI, nI, csf_i, excitInfo)
p_guga = calc_pgen_mol_guga_single_guga(ilutI, nI, ilutJ, nJ, excitInfo)
pgen = p_orbs * p_guga
end function calc_pgen_mol_guga_single