cisd
This module contains a CI of single and double excitations.
The user point of view
The cisd program performs the CI of the ROHF-like + all single and double 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
scf()
program gave the lowest SCF solution. In combination withsave_natorb()
it can produce new MOs in order to reperform anscf()
optimization.Excited states calculations: generate guess for all the
determinants n_states
wave functions, that will be used by thefci()
program.
The main keywords/options to be used are:
determinants n_states
: number of states to consider for the CISD calculationdeterminants s2_eig
: force all states to have the desired value of \(S^2\)determinants expected_s2
: desired value of \(S^2\)
The programmer point of view
This module have been built by setting the following rules:
The only generator determinant is the Hartree-Fock (single-reference method)
All generated determinants are included in the wave function (no perturbative selection)
These rules are set in the H_apply.irp.f
file.
EZFIO parameters
- energy
Variational CISD energy
Programs
Subroutines / functions
- h_apply_cisd:
File :
h_apply.irp.f_shell_12
subroutine H_apply_cisd()
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:
generators_bitmask
h_apply_buffer_allocated
mo_num
mo_two_e_integrals_in_map
n_det
n_det_generators
n_int
n_states
psi_coef
psi_det_generators
psi_det
psi_det_generators
s2_eig
Called by:
run_cisd()
Calls:
build_fock_tmp()
copy_h_apply_buffer_to_wf()
dsort()
h_apply_cisd_diexc()
h_apply_cisd_monoexc()
make_s2_eigenfunction()
wall_time()
Touches:
n_det
psi_occ_pattern
c0_weight
psi_coef
psi_det_sorted_bit
psi_det
psi_det_size
psi_det_sorted_bit
psi_occ_pattern
- h_apply_cisd_diexc:
File :
h_apply.irp.f_shell_12
subroutine H_apply_cisd_diexc(key_in, key_prev, hole_1,particl_1, hole_2, particl_2, fock_diag_tmp, i_generator, iproc_in )
Needs:
mo_num
n_det
n_int
Called by:
h_apply_cisd()
Calls:
h_apply_cisd_diexcp()
- h_apply_cisd_diexcorg:
File :
h_apply.irp.f_shell_12
subroutine H_apply_cisd_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:
elec_alpha_num
mo_num
n_int
Called by:
h_apply_cisd_diexcp()
Calls:
bitstring_to_list_ab()
fill_h_apply_buffer_no_selection()
- h_apply_cisd_diexcp:
File :
h_apply.irp.f_shell_12
subroutine H_apply_cisd_diexcP(key_in, fs1, fh1, particl_1, fs2, fh2, particl_2, fock_diag_tmp, i_generator, iproc_in )
Needs:
mo_num
n_det
n_int
Called by:
h_apply_cisd_diexc()
Calls:
h_apply_cisd_diexcorg()
- h_apply_cisd_monoexc:
File :
h_apply.irp.f_shell_12
subroutine H_apply_cisd_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:
elec_alpha_num
mo_num
n_int
Called by:
h_apply_cisd()
Calls:
bitstring_to_list_ab()
fill_h_apply_buffer_no_selection()
- h_apply_cisd_sym:
File :
h_apply.irp.f_shell_12
subroutine H_apply_cisd_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:
generators_bitmask
h_apply_buffer_allocated
mo_num
mo_two_e_integrals_in_map
n_det
n_det_generators
n_int
n_states
psi_coef
psi_det_generators
psi_det
psi_det_generators
s2_eig
Called by:
run_cisd()
Calls:
build_fock_tmp()
copy_h_apply_buffer_to_wf()
dsort()
h_apply_cisd_sym_diexc()
h_apply_cisd_sym_monoexc()
make_s2_eigenfunction()
wall_time()
Touches:
n_det
psi_occ_pattern
c0_weight
psi_coef
psi_det_sorted_bit
psi_det
psi_det_size
psi_det_sorted_bit
psi_occ_pattern
- h_apply_cisd_sym_diexc:
File :
h_apply.irp.f_shell_12
subroutine H_apply_cisd_sym_diexc(key_in, key_prev, hole_1,particl_1, hole_2, particl_2, fock_diag_tmp, i_generator, iproc_in )
Needs:
mo_num
n_det
n_int
Called by:
h_apply_cisd_sym()
Calls:
h_apply_cisd_sym_diexcp()
- h_apply_cisd_sym_diexcorg:
File :
h_apply.irp.f_shell_12
subroutine H_apply_cisd_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:
elec_alpha_num
mo_num
n_int
Called by:
h_apply_cisd_sym_diexcp()
Calls:
bitstring_to_list_ab()
connected_to_hf()
fill_h_apply_buffer_no_selection()
- h_apply_cisd_sym_diexcp:
File :
h_apply.irp.f_shell_12
subroutine H_apply_cisd_sym_diexcP(key_in, fs1, fh1, particl_1, fs2, fh2, particl_2, fock_diag_tmp, i_generator, iproc_in )
Needs:
mo_num
n_det
n_int
Called by:
h_apply_cisd_sym_diexc()
Calls:
h_apply_cisd_sym_diexcorg()
- h_apply_cisd_sym_monoexc:
File :
h_apply.irp.f_shell_12
subroutine H_apply_cisd_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:
elec_alpha_num
mo_num
n_int
Called by:
h_apply_cisd_sym()
Calls:
bitstring_to_list_ab()
connected_to_hf()
fill_h_apply_buffer_no_selection()
- run_cisd:
File :
cisd_routine.irp.f
subroutine run_cisd
Needs:
ci_electronic_energy
ci_energy
n_det
n_states
pseudo_sym
psi_coef
Calls:
ezfio_set_cisd_energy()
h_apply_cisd()
h_apply_cisd_sym()
save_wavefunction()
Touches:
n_det
psi_occ_pattern
c0_weight
psi_coef
psi_det_sorted_bit
psi_det
psi_det_size
psi_det_sorted_bit
psi_occ_pattern