.. _module_cis: .. program:: cis .. default-role:: option === cis === This module contains a |CIS| program. The user point of view ---------------------- The :ref:`cis` program performs the CI to obtain the ROHF reference + all single excitations on top of it. This program can be very useful to: * **Ground state calculations**: generate a guess for the ground state wave function if one is not sure that the :ref:`scf` program gave the lowest |SCF| solution. In combination with :ref:`save_natorb` it can produce new |MOs| in order to reperform an :ref:`scf` optimization. * **Excited states calculations**: generate guesses for all the :option:`determinants n_states` wave functions, that will be used by the :ref:`fci` program. The main keywords/options to be used are: * :option:`determinants n_states`: number of states to consider for the |CIS| calculation * :option:`determinants s2_eig`: force all states to have the desired value of |S^2| * :option:`determinants expected_s2`: desired value of |S^2| The programmer's point of view ------------------------------ This module was built by setting the following rules: * The only generator determinant is the Hartree-Fock (single-reference method) * All generated singly excited determinants are included in the wave function (no perturbative selection) These rules are set in the ``H_apply.irp.f`` file. EZFIO parameters ---------------- .. option:: energy Variational |CIS| energy Programs -------- * :ref:`cis` Subroutines / functions ----------------------- .. c:function:: h_apply_cis: File : :file:`h_apply.irp.f_shell_13` .. code:: fortran subroutine H_apply_cis() Calls H_apply on the |HF| determinant and selects all connected single and double excitations (of the same symmetry). Auto-generated by the ``generate_h_apply`` script. Needs: .. hlist:: :columns: 3 * :c:data:`generators_bitmask` * :c:data:`h_apply_buffer_allocated` * :c:data:`mo_num` * :c:data:`mo_two_e_integrals_in_map` * :c:data:`n_det` * :c:data:`n_det_generators` * :c:data:`n_int` * :c:data:`n_states` * :c:data:`psi_coef` * :c:data:`psi_det_generators` * :c:data:`psi_det` * :c:data:`psi_det_generators` * :c:data:`s2_eig` Calls: .. hlist:: :columns: 3 * :c:func:`build_fock_tmp` * :c:func:`copy_h_apply_buffer_to_wf` * :c:func:`dsort` * :c:func:`h_apply_cis_diexc` * :c:func:`h_apply_cis_monoexc` * :c:func:`make_s2_eigenfunction` * :c:func:`wall_time` Touches: .. hlist:: :columns: 3 * :c:data:`psi_configuration` * :c:data:`n_det` * :c:data:`c0_weight` * :c:data:`psi_coef` * :c:data:`psi_det_sorted_bit` * :c:data:`psi_configuration` * :c:data:`psi_det` * :c:data:`psi_det_size` * :c:data:`psi_det_sorted_bit` .. c:function:: h_apply_cis_diexc: File : :file:`h_apply.irp.f_shell_13` .. code:: fortran subroutine H_apply_cis_diexc(key_in, key_prev, hole_1,particl_1, hole_2, particl_2, fock_diag_tmp, i_generator, iproc_in ) Needs: .. hlist:: :columns: 3 * :c:data:`mo_num` * :c:data:`n_det` * :c:data:`n_int` Called by: .. hlist:: :columns: 3 * :c:func:`h_apply_cis` Calls: .. hlist:: :columns: 3 * :c:func:`h_apply_cis_diexcp` .. c:function:: h_apply_cis_diexcorg: File : :file:`h_apply.irp.f_shell_13` .. code:: fortran subroutine H_apply_cis_diexcOrg(key_in,key_mask,hole_1,particl_1,hole_2, particl_2, fock_diag_tmp, i_generator, iproc_in ) Generate all double excitations of key_in using the bit masks of holes and particles. Assume N_int is already provided. Needs: .. hlist:: :columns: 3 * :c:data:`elec_alpha_num` * :c:data:`mo_num` * :c:data:`n_int` Called by: .. hlist:: :columns: 3 * :c:func:`h_apply_cis_diexcp` Calls: .. hlist:: :columns: 3 * :c:func:`bitstring_to_list_ab` * :c:func:`fill_h_apply_buffer_no_selection` .. c:function:: h_apply_cis_diexcp: File : :file:`h_apply.irp.f_shell_13` .. code:: fortran subroutine H_apply_cis_diexcP(key_in, fs1, fh1, particl_1, fs2, fh2, particl_2, fock_diag_tmp, i_generator, iproc_in ) Needs: .. hlist:: :columns: 3 * :c:data:`mo_num` * :c:data:`n_det` * :c:data:`n_int` Called by: .. hlist:: :columns: 3 * :c:func:`h_apply_cis_diexc` Calls: .. hlist:: :columns: 3 * :c:func:`h_apply_cis_diexcorg` .. c:function:: h_apply_cis_monoexc: File : :file:`h_apply.irp.f_shell_13` .. code:: fortran subroutine H_apply_cis_monoexc(key_in, hole_1,particl_1,fock_diag_tmp,i_generator,iproc_in ) Generate all single excitations of key_in using the bit masks of holes and particles. Assume N_int is already provided. Needs: .. hlist:: :columns: 3 * :c:data:`elec_alpha_num` * :c:data:`mo_num` * :c:data:`n_int` Called by: .. hlist:: :columns: 3 * :c:func:`h_apply_cis` Calls: .. hlist:: :columns: 3 * :c:func:`bitstring_to_list_ab` * :c:func:`fill_h_apply_buffer_no_selection` .. c:function:: h_apply_cis_sym: File : :file:`h_apply.irp.f_shell_13` .. code:: fortran subroutine H_apply_cis_sym() Calls H_apply on the |HF| determinant and selects all connected single and double excitations (of the same symmetry). Auto-generated by the ``generate_h_apply`` script. Needs: .. hlist:: :columns: 3 * :c:data:`generators_bitmask` * :c:data:`h_apply_buffer_allocated` * :c:data:`mo_num` * :c:data:`mo_two_e_integrals_in_map` * :c:data:`n_det` * :c:data:`n_det_generators` * :c:data:`n_int` * :c:data:`n_states` * :c:data:`psi_coef` * :c:data:`psi_det_generators` * :c:data:`psi_det` * :c:data:`psi_det_generators` * :c:data:`s2_eig` Calls: .. hlist:: :columns: 3 * :c:func:`build_fock_tmp` * :c:func:`copy_h_apply_buffer_to_wf` * :c:func:`dsort` * :c:func:`h_apply_cis_sym_diexc` * :c:func:`h_apply_cis_sym_monoexc` * :c:func:`make_s2_eigenfunction` * :c:func:`wall_time` Touches: .. hlist:: :columns: 3 * :c:data:`psi_configuration` * :c:data:`n_det` * :c:data:`c0_weight` * :c:data:`psi_coef` * :c:data:`psi_det_sorted_bit` * :c:data:`psi_configuration` * :c:data:`psi_det` * :c:data:`psi_det_size` * :c:data:`psi_det_sorted_bit` .. c:function:: h_apply_cis_sym_diexc: File : :file:`h_apply.irp.f_shell_13` .. code:: fortran subroutine H_apply_cis_sym_diexc(key_in, key_prev, hole_1,particl_1, hole_2, particl_2, fock_diag_tmp, i_generator, iproc_in ) Needs: .. hlist:: :columns: 3 * :c:data:`mo_num` * :c:data:`n_det` * :c:data:`n_int` Called by: .. hlist:: :columns: 3 * :c:func:`h_apply_cis_sym` Calls: .. hlist:: :columns: 3 * :c:func:`h_apply_cis_sym_diexcp` .. c:function:: h_apply_cis_sym_diexcorg: File : :file:`h_apply.irp.f_shell_13` .. code:: fortran subroutine H_apply_cis_sym_diexcOrg(key_in,key_mask,hole_1,particl_1,hole_2, particl_2, fock_diag_tmp, i_generator, iproc_in ) Generate all double excitations of key_in using the bit masks of holes and particles. Assume N_int is already provided. Needs: .. hlist:: :columns: 3 * :c:data:`elec_alpha_num` * :c:data:`mo_num` * :c:data:`n_int` Called by: .. hlist:: :columns: 3 * :c:func:`h_apply_cis_sym_diexcp` Calls: .. hlist:: :columns: 3 * :c:func:`bitstring_to_list_ab` * :c:func:`connected_to_hf` * :c:func:`fill_h_apply_buffer_no_selection` .. c:function:: h_apply_cis_sym_diexcp: File : :file:`h_apply.irp.f_shell_13` .. code:: fortran subroutine H_apply_cis_sym_diexcP(key_in, fs1, fh1, particl_1, fs2, fh2, particl_2, fock_diag_tmp, i_generator, iproc_in ) Needs: .. hlist:: :columns: 3 * :c:data:`mo_num` * :c:data:`n_det` * :c:data:`n_int` Called by: .. hlist:: :columns: 3 * :c:func:`h_apply_cis_sym_diexc` Calls: .. hlist:: :columns: 3 * :c:func:`h_apply_cis_sym_diexcorg` .. c:function:: h_apply_cis_sym_monoexc: File : :file:`h_apply.irp.f_shell_13` .. code:: fortran subroutine H_apply_cis_sym_monoexc(key_in, hole_1,particl_1,fock_diag_tmp,i_generator,iproc_in ) Generate all single excitations of key_in using the bit masks of holes and particles. Assume N_int is already provided. Needs: .. hlist:: :columns: 3 * :c:data:`elec_alpha_num` * :c:data:`mo_num` * :c:data:`n_int` Called by: .. hlist:: :columns: 3 * :c:func:`h_apply_cis_sym` Calls: .. hlist:: :columns: 3 * :c:func:`bitstring_to_list_ab` * :c:func:`connected_to_hf` * :c:func:`fill_h_apply_buffer_no_selection`