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mirror of https://github.com/QuantumPackage/qp2.git synced 2024-11-07 05:53:37 +01:00

added lccsd

This commit is contained in:
eginer 2023-08-09 16:23:09 +02:00
parent 9eba86fea0
commit 0440def363
4 changed files with 148 additions and 0 deletions

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@ -5,3 +5,11 @@ interface: ezfio
size: (determinants.n_states) size: (determinants.n_states)
[lcc_energy]
type: double precision
doc: lccsd energy
interface: ezfio
size: (determinants.n_states)

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@ -1,3 +1,4 @@
selectors_full selectors_full
single_ref_method single_ref_method
davidson_undressed davidson_undressed
dav_general_mat

95
src/cisd/lccsd.irp.f Normal file
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@ -0,0 +1,95 @@
program lccsd
implicit none
BEGIN_DOC
! Linerarized CCSD
!
! This program takes a reference Slater determinant of ROHF-like occupancy,
!
! and performs all single and double excitations on top of it, disregarding
! spatial symmetry and compute the "n_states" lowest eigenstates of that CI
! matrix (see :option:`determinants n_states`).
!
! This program can be useful in many cases:
!
! * **Ground state calculation**: if even after a :c:func:`cis` calculation, natural
! orbitals (see :c:func:`save_natorb`) and then :c:func:`scf` optimization, you are not sure to have the lowest scf
! solution,
! do the same strategy with the :c:func:`cisd` executable instead of the :c:func:`cis` exectuable to generate the natural
! orbitals as a guess for the :c:func:`scf`.
!
!
!
! * **Excited states calculations**: the lowest excited states are much likely to
! be dominanted by single- or double-excitations.
! Therefore, running a :c:func:`cisd` will save the "n_states" lowest states within
! the CISD space
! in the |EZFIO| directory, which can afterward be used as guess wave functions
! for a further multi-state fci calculation if you specify "read_wf" = True
! before running the fci executable (see :option:`determinants read_wf`).
! Also, if you specify "s2_eig" = True, the cisd will only retain states
! having the good value :math:`S^2` value
! (see :option:`determinants expected_s2` and :option:`determinants s2_eig`).
! If "s2_eig" = False, it will take the lowest n_states, whatever
! multiplicity they are.
!
!
!
! Note: if you would like to discard some orbitals, use
! :ref:`qp_set_mo_class` to specify:
!
! * "core" orbitals which will be always doubly occupied
!
! * "act" orbitals where an electron can be either excited from or to
!
! * "del" orbitals which will be never occupied
!
END_DOC
PROVIDE N_states
read_wf = .False.
TOUCH read_wf
call run
end
subroutine run
implicit none
if(pseudo_sym)then
call H_apply_cisd_sym
else
call H_apply_cisd
endif
call get_lccsd_2
end
subroutine get_lccsd_2
implicit none
integer :: i,k
double precision :: cisdq(N_states), delta_e
double precision,external :: diag_h_mat_elem
psi_coef = lccsd_coef
SOFT_TOUCH psi_coef
call save_wavefunction_truncated(save_threshold)
call ezfio_set_cisd_lcc_energy(lccsd_energies)
print *, 'N_det = ', N_det
print*,''
print*,'******************************'
print *, 'LCCSD Energies'
do i = 1,N_states
print *, i, lccsd_energies(i)
enddo
if (N_states > 1) then
print*,'******************************'
print*,'Excitation energies (au) (LCCSD)'
do i = 2, N_states
print*, i ,lccsd_energies(i) - lccsd_energies(1)
enddo
print*,''
print*,'******************************'
print*,'Excitation energies (eV) (LCCSD)'
do i = 2, N_states
print*, i ,(lccsd_energies(i) - lccsd_energies(1)) * ha_to_ev
enddo
endif
end

44
src/cisd/lccsd_prov.irp.f Normal file
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BEGIN_PROVIDER [ double precision, lccsd_coef, (N_det, N_states)]
&BEGIN_PROVIDER [ double precision, lccsd_energies, (N_states)]
implicit none
double precision, allocatable :: Dress_jj(:), H_jj(:), u_in(:,:)
double precision :: ebefore, eafter, ecorr, thresh
integer :: i,it
logical :: converged
external H_u_0_nstates_openmp
allocate(Dress_jj(N_det),H_jj(N_det),u_in(N_det,N_states_diag))
thresh = 1.d-6
converged = .False.
Dress_jj = 0.d0
u_in = 0.d0
it = 0
! initial guess
do i = 1, N_states_diag
u_in(i,i) = 1.d0
enddo
do i = 1,N_det
call i_H_j(psi_det(1,1,i),psi_det(1,1,i),N_int,H_jj(i))
enddo
ebefore = H_jj(1)
do while (.not.converged)
it += 1
print*,'N_det = ',N_det
call davidson_general_ext_rout_diag_dressed(u_in,H_jj,Dress_jj,lccsd_energies,&
N_det,N_states,N_states_diag,converged,H_u_0_nstates_openmp)
ecorr = lccsd_energies(1) - H_jj(1)
print*,'---------------------'
print*,'it = ',it
print*,'ecorr = ',ecorr
Dress_jj(1) = 0.d0
do i = 2, N_det
Dress_jj(i) = ecorr
enddo
eafter = lccsd_energies(1)
converged = (dabs(eafter - ebefore).lt.thresh)
ebefore = eafter
enddo
do i = 1, N_states
lccsd_coef(1:N_det,i) = u_in(1:N_det,i)
enddo
END_PROVIDER