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qp2/src/dav_general_mat/dav_general.irp.f
Anthony Scemama 0242e9c376
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2023-07-04 22:17:31 +02:00

436 lines
12 KiB
Fortran

subroutine davidson_general(u_in,H_jj,energies,dim_in,sze,N_st,N_st_diag_in,converged,h_mat)
use mmap_module
implicit none
BEGIN_DOC
! Davidson diagonalization with specific diagonal elements of the H matrix
!
! H_jj : specific diagonal H matrix elements to diagonalize de Davidson
!
! u_in : guess coefficients on the various states. Overwritten on exit
!
! dim_in : leftmost dimension of u_in
!
! sze : Number of determinants
!
! N_st : Number of eigenstates
!
! N_st_diag_in : Number of states in which H is diagonalized. Assumed > sze
!
! Initial guess vectors are not necessarily orthonormal
END_DOC
integer, intent(in) :: dim_in, sze, N_st, N_st_diag_in
double precision, intent(in) :: H_jj(sze),h_mat(sze,sze)
double precision, intent(inout) :: u_in(dim_in,N_st_diag_in)
double precision, intent(out) :: energies(N_st)
integer :: iter, N_st_diag
integer :: i,j,k,l,m
logical, intent(inout) :: converged
double precision, external :: u_dot_v, u_dot_u
integer :: k_pairs, kl
integer :: iter2, itertot
double precision, allocatable :: y(:,:), h(:,:), lambda(:)
double precision :: diag_h_mat_elem
double precision, allocatable :: residual_norm(:)
character*(16384) :: write_buffer
double precision :: to_print(2,N_st)
double precision :: cpu, wall
integer :: shift, shift2, itermax, istate
double precision :: r1, r2, alpha
integer :: nproc_target
integer :: order(N_st_diag_in)
double precision :: cmax
double precision, allocatable :: U(:,:), overlap(:,:)!, S_d(:,:)
double precision, pointer :: W(:,:)
logical :: disk_based
double precision :: energy_shift(N_st_diag_in*davidson_sze_max)
include 'constants.include.F'
N_st_diag = N_st_diag_in
!DIR$ ATTRIBUTES ALIGN : $IRP_ALIGN :: U, W, y, h, lambda
if (N_st_diag*3 > sze) then
print *, 'error in Davidson :'
print *, 'Increase n_det_max_full to ', N_st_diag*3
stop -1
endif
itermax = max(2,min(davidson_sze_max, sze/N_st_diag))+1
itertot = 0
if (state_following) then
allocate(overlap(N_st_diag*itermax, N_st_diag*itermax))
else
allocate(overlap(1,1)) ! avoid 'if' for deallocate
endif
overlap = 0.d0
provide threshold_davidson !nthreads_davidson
call write_time(6)
write(6,'(A)') ''
write(6,'(A)') 'Davidson Diagonalization'
write(6,'(A)') '------------------------'
write(6,'(A)') ''
! Find max number of cores to fit in memory
! -----------------------------------------
nproc_target = nproc
double precision :: rss
integer :: maxab
maxab = sze
m=1
disk_based = .False.
call resident_memory(rss)
do
r1 = 8.d0 * &! bytes
( dble(sze)*(N_st_diag*itermax) &! U
+ 1.d0*dble(sze*m)*(N_st_diag*itermax) &! W
+ 2.0d0*(N_st_diag*itermax)**2 &! h,y
+ 2.d0*(N_st_diag*itermax) &! s2,lambda
+ 1.d0*(N_st_diag) &! residual_norm
! In H_S2_u_0_nstates_zmq
+ 3.d0*(N_st_diag*N_det) &! u_t, v_t, s_t on collector
+ 3.d0*(N_st_diag*N_det) &! u_t, v_t, s_t on slave
+ 0.5d0*maxab &! idx0 in H_S2_u_0_nstates_openmp_work_*
+ nproc_target * &! In OMP section
( 1.d0*(N_int*maxab) &! buffer
+ 3.5d0*(maxab) ) &! singles_a, singles_b, doubles, idx
) / 1024.d0**3
if (nproc_target == 0) then
call check_mem(r1,irp_here)
nproc_target = 1
exit
endif
if (r1+rss < qp_max_mem) then
exit
endif
if (itermax > 4) then
itermax = itermax - 1
else if (m==1.and.disk_based_davidson) then
m=0
disk_based = .True.
itermax = 6
else
nproc_target = nproc_target - 1
endif
enddo
nthreads_davidson = nproc_target
TOUCH nthreads_davidson
call write_int(6,N_st,'Number of states')
call write_int(6,N_st_diag,'Number of states in diagonalization')
call write_int(6,sze,'Number of basis functions')
call write_int(6,nproc_target,'Number of threads for diagonalization')
call write_double(6, r1, 'Memory(Gb)')
if (disk_based) then
print *, 'Using swap space to reduce RAM'
endif
!---------------
write(6,'(A)') ''
write_buffer = '====='
do i=1,N_st
write_buffer = trim(write_buffer)//' ================ ==========='
enddo
write(6,'(A)') write_buffer(1:6+41*N_st)
write_buffer = 'Iter'
do i=1,N_st
write_buffer = trim(write_buffer)//' Energy Residual '
enddo
write(6,'(A)') write_buffer(1:6+41*N_st)
write_buffer = '====='
do i=1,N_st
write_buffer = trim(write_buffer)//' ================ ==========='
enddo
write(6,'(A)') write_buffer(1:6+41*N_st)
! if (disk_based) then
! ! Create memory-mapped files for W and S
! type(c_ptr) :: ptr_w, ptr_s
! integer :: fd_s, fd_w
! call mmap(trim(ezfio_work_dir)//'davidson_w', (/int(sze,8),int(N_st_diag*itermax,8)/),&
! 8, fd_w, .False., ptr_w)
! call mmap(trim(ezfio_work_dir)//'davidson_s', (/int(sze,8),int(N_st_diag*itermax,8)/),&
! 4, fd_s, .False., ptr_s)
! call c_f_pointer(ptr_w, w, (/sze,N_st_diag*itermax/))
! call c_f_pointer(ptr_s, s, (/sze,N_st_diag*itermax/))
! else
allocate(W(sze,N_st_diag*itermax))
! endif
allocate( &
! Large
U(sze,N_st_diag*itermax), &
! Small
h(N_st_diag*itermax,N_st_diag*itermax), &
y(N_st_diag*itermax,N_st_diag*itermax), &
residual_norm(N_st_diag), &
lambda(N_st_diag*itermax))
h = 0.d0
U = 0.d0
y = 0.d0
ASSERT (N_st > 0)
ASSERT (N_st_diag >= N_st)
ASSERT (sze > 0)
! Davidson iterations
! ===================
converged = .False.
! Initialize from N_st to N_st_diat with gaussian random numbers
! to be sure to have overlap with any eigenvectors
do k=N_st+1,N_st_diag
u_in(k,k) = 10.d0
do i=1,sze
call random_number(r1)
call random_number(r2)
r1 = dsqrt(-2.d0*dlog(r1))
r2 = dtwo_pi*r2
u_in(i,k) = r1*dcos(r2)
enddo
enddo
! Normalize all states
do k=1,N_st_diag
call normalize(u_in(:,k),sze)
enddo
! Copy from the guess input "u_in" to the working vectors "U"
do k=1,N_st_diag
do i=1,sze
U(i,k) = u_in(i,k)
enddo
enddo
do while (.not.converged)
itertot = itertot+1
if (itertot == 8) then
exit
endif
do iter=1,itermax-1
shift = N_st_diag*(iter-1)
shift2 = N_st_diag*iter
if ((iter > 1).or.(itertot == 1)) then
! Compute |W_k> = \sum_i |i><i|H|u_k>
! -----------------------------------
! Gram-Smitt to orthogonalize all new guess with the previous vectors
call ortho_qr(U,size(U,1),sze,shift2)
call ortho_qr(U,size(U,1),sze,shift2)
! call H_S2_u_0_nstates_openmp(W(:,shift+1),U(:,shift+1),N_st_diag,sze)
call hpsi(W(:,shift+1),U(:,shift+1),N_st_diag,sze,h_mat)
else
! Already computed in update below
continue
endif
! Compute h_kl = <u_k | W_l> = <u_k| H |u_l>
! -------------------------------------------
call dgemm('T','N', shift2, shift2, sze, &
1.d0, U, size(U,1), W, size(W,1), &
0.d0, h, size(h,1))
! Diagonalize h y = lambda y
! ---------------
call lapack_diag(lambda,y,h,size(h,1),shift2)
if (state_following) then
overlap = -1.d0
do k=1,shift2
do i=1,shift2
overlap(k,i) = dabs(y(k,i))
enddo
enddo
do k=1,N_st
cmax = -1.d0
do i=1,N_st
if (overlap(i,k) > cmax) then
cmax = overlap(i,k)
order(k) = i
endif
enddo
do i=1,N_st_diag
overlap(order(k),i) = -1.d0
enddo
enddo
overlap = y
do k=1,N_st
l = order(k)
if (k /= l) then
y(1:shift2,k) = overlap(1:shift2,l)
endif
enddo
do k=1,N_st
overlap(k,1) = lambda(k)
enddo
do k=1,N_st
l = order(k)
if (k /= l) then
lambda(k) = overlap(l,1)
endif
enddo
endif
! Express eigenvectors of h in the determinant basis
! --------------------------------------------------
call dgemm('N','N', sze, N_st_diag, shift2, &
1.d0, U, size(U,1), y, size(y,1), 0.d0, U(:,shift2+1), size(U,1))
call dgemm('N','N', sze, N_st_diag, shift2, &
1.d0, W, size(W,1), y, size(y,1), 0.d0, W(:,shift2+1), size(W,1))
! Compute residual vector and davidson step
! -----------------------------------------
!$OMP PARALLEL DO DEFAULT(SHARED) PRIVATE(i,k)
do k=1,N_st_diag
do i=1,sze
U(i,shift2+k) = &
(lambda(k) * U(i,shift2+k) - W(i,shift2+k) ) &
/max(H_jj(i) - lambda (k),1.d-2)
enddo
if (k <= N_st) then
residual_norm(k) = u_dot_u(U(:,shift2+k),sze)
to_print(1,k) = lambda(k)
to_print(2,k) = residual_norm(k)
endif
enddo
!$OMP END PARALLEL DO
if ((itertot>1).and.(iter == 1)) then
!don't print
continue
else
write(*,'(1X,I3,1X,100(1X,F16.10,1X,F11.6,1X,ES11.3))') iter-1, to_print(1:2,1:N_st)
endif
! Check convergence
if (iter > 1) then
converged = dabs(maxval(residual_norm(1:N_st))) < threshold_davidson
endif
do k=1,N_st
if (residual_norm(k) > 1.e8) then
print *, 'Davidson failed'
stop -1
endif
enddo
if (converged) then
exit
endif
logical, external :: qp_stop
if (qp_stop()) then
converged = .True.
exit
endif
enddo
call dgemm('N','N', sze, N_st_diag, shift2, 1.d0, &
W, size(W,1), y, size(y,1), 0.d0, u_in, size(u_in,1))
do k=1,N_st_diag
do i=1,sze
W(i,k) = u_in(i,k)
enddo
enddo
call dgemm('N','N', sze, N_st_diag, shift2, 1.d0, &
U, size(U,1), y, size(y,1), 0.d0, u_in, size(u_in,1))
do k=1,N_st_diag
do i=1,sze
U(i,k) = u_in(i,k)
enddo
enddo
call ortho_qr(U,size(U,1),sze,N_st_diag)
call ortho_qr(U,size(U,1),sze,N_st_diag)
do j=1,N_st_diag
k=1
do while ((k<sze).and.(U(k,j) == 0.d0))
k = k+1
enddo
if (U(k,j) * u_in(k,j) < 0.d0) then
do i=1,sze
W(i,j) = -W(i,j)
enddo
endif
enddo
enddo
do k=1,N_st
energies(k) = lambda(k)
enddo
write_buffer = '====='
do i=1,N_st
write_buffer = trim(write_buffer)//' ================ ==========='
enddo
write(6,'(A)') trim(write_buffer)
write(6,'(A)') ''
call write_time(6)
deallocate(W)
deallocate ( &
residual_norm, &
U, h, &
y, &
lambda &
)
deallocate(overlap)
FREE nthreads_davidson
end
subroutine hpsi(v,u,N_st,sze,h_mat)
use bitmasks
implicit none
BEGIN_DOC
! Computes $v = H | u \rangle$ and
END_DOC
integer, intent(in) :: N_st,sze
double precision, intent(in) :: u(sze,N_st),h_mat(sze,sze)
double precision, intent(inout) :: v(sze,N_st)
integer :: i,j,istate
v = 0.d0
do istate = 1, N_st
do i = 1, sze
do j = 1, sze
v(i,istate) += h_mat(j,i) * u(j,istate)
enddo
enddo
enddo
end