subroutine hcore_guess
  BEGIN_DOC
! Produce `H_core` MO orbital
  END_DOC
  implicit none
  character*(64)                 :: label
  label = "Guess"
  if (is_complex) then
    call mo_as_eigvectors_of_mo_matrix_complex(mo_one_e_integrals_complex,  &
                                       size(mo_one_e_integrals_complex,1),  &
                                       size(mo_one_e_integrals_complex,2),label,1,.false.)
    call save_mos
    SOFT_TOUCH mo_coef_complex mo_label

  else
    call mo_as_eigvectors_of_mo_matrix(mo_one_e_integrals,          &
                                       size(mo_one_e_integrals,1),  &
                                       size(mo_one_e_integrals,2),label,1,.false.)
    call save_mos
    SOFT_TOUCH mo_coef mo_label
  endif
end