mirror of
https://gitlab.com/scemama/qp_plugins_scemama.git
synced 2024-12-23 04:43:38 +01:00
75 lines
2.1 KiB
Fortran
75 lines
2.1 KiB
Fortran
|
|
BEGIN_PROVIDER [real*8, gradvec_old, (nMonoEx)]
|
|
BEGIN_DOC
|
|
! calculate the orbital gradient <Psi| H E_pq |Psi> by hand, i.e. for
|
|
! each determinant I we determine the string E_pq |I> (alpha and beta
|
|
! separately) and generate <Psi|H E_pq |I>
|
|
! sum_I c_I <Psi|H E_pq |I> is then the pq component of the orbital
|
|
! gradient
|
|
! E_pq = a^+_pa_q + a^+_Pa_Q
|
|
END_DOC
|
|
implicit none
|
|
integer :: ii,tt,aa,indx,ihole,ipart,istate
|
|
real*8 :: res
|
|
|
|
do indx=1,nMonoEx
|
|
ihole=excit(1,indx)
|
|
ipart=excit(2,indx)
|
|
call calc_grad_elem(ihole,ipart,res)
|
|
gradvec_old(indx)=res
|
|
end do
|
|
|
|
real*8 :: norm_grad
|
|
norm_grad=0.d0
|
|
do indx=1,nMonoEx
|
|
norm_grad+=gradvec_old(indx)*gradvec_old(indx)
|
|
end do
|
|
norm_grad=sqrt(norm_grad)
|
|
if (bavard) then
|
|
write(6,*)
|
|
write(6,*) ' Norm of the orbital gradient (via <0|EH|0>) : ', norm_grad
|
|
write(6,*)
|
|
endif
|
|
|
|
|
|
END_PROVIDER
|
|
|
|
subroutine calc_grad_elem(ihole,ipart,res)
|
|
BEGIN_DOC
|
|
! eq 18 of Siegbahn et al, Physica Scripta 1980
|
|
! we calculate 2 <Psi| H E_pq | Psi>, q=hole, p=particle
|
|
END_DOC
|
|
implicit none
|
|
integer :: ihole,ipart,mu,iii,ispin,ierr,nu,istate
|
|
real*8 :: res
|
|
integer(bit_kind), allocatable :: det_mu(:,:),det_mu_ex(:,:)
|
|
real*8 :: i_H_psi_array(N_states),phase
|
|
allocate(det_mu(N_int,2))
|
|
allocate(det_mu_ex(N_int,2))
|
|
|
|
res=0.D0
|
|
|
|
do mu=1,n_det
|
|
! get the string of the determinant
|
|
call det_extract(det_mu,mu,N_int)
|
|
do ispin=1,2
|
|
! do the monoexcitation on it
|
|
call det_copy(det_mu,det_mu_ex,N_int)
|
|
call do_signed_mono_excitation(det_mu,det_mu_ex,nu &
|
|
,ihole,ipart,ispin,phase,ierr)
|
|
if (ierr.eq.1) then
|
|
call i_H_psi(det_mu_ex,psi_det,psi_coef,N_int &
|
|
,N_det,N_det,N_states,i_H_psi_array)
|
|
do istate=1,N_states
|
|
res+=i_H_psi_array(istate)*psi_coef(mu,istate)*phase
|
|
end do
|
|
end if
|
|
end do
|
|
end do
|
|
|
|
! state-averaged gradient
|
|
res*=2.D0/dble(N_states)
|
|
|
|
end subroutine calc_grad_elem
|
|
|