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mirror of https://github.com/LCPQ/quantum_package synced 2024-06-02 11:25:26 +02:00
quantum_package/src/Determinants/connected_to_ref.irp.f

360 lines
9.3 KiB
Fortran

integer*8 function det_search_key(det,Nint)
use bitmasks
implicit none
BEGIN_DOC
! Return an integer*8 corresponding to a determinant index for searching
END_DOC
integer, intent(in) :: Nint
integer(bit_kind), intent(in) :: det(Nint,2)
integer :: i
det_search_key = iand(det(1,1),det(1,2))
do i=2,Nint
det_search_key = ieor(det_search_key,iand(det(i,1),det(i,2)))
enddo
det_search_key = iand(huge(det(1,1)),det_search_key)
end
integer*8 function occ_pattern_search_key(det,Nint)
use bitmasks
implicit none
BEGIN_DOC
! Return an integer*8 corresponding to a determinant index for searching
END_DOC
integer, intent(in) :: Nint
integer(bit_kind), intent(in) :: det(Nint,2)
integer :: i
occ_pattern_search_key = ieor(det(1,1),det(1,2))
do i=2,Nint
occ_pattern_search_key = ieor(occ_pattern_search_key,iand(det(i,1),det(i,2)))
enddo
occ_pattern_search_key = iand(huge(det(1,1)),occ_pattern_search_key)
end
logical function is_in_wavefunction(key,Nint,Ndet)
use bitmasks
implicit none
BEGIN_DOC
! True if the determinant ``det`` is in the wave function
END_DOC
integer, intent(in) :: Nint, Ndet
integer(bit_kind), intent(in) :: key(Nint,2)
integer, external :: get_index_in_psi_det_sorted_bit
!DIR$ FORCEINLINE
is_in_wavefunction = get_index_in_psi_det_sorted_bit(key,Nint) > 0
end
integer function get_index_in_psi_det_sorted_bit(key,Nint)
use bitmasks
BEGIN_DOC
! Returns the index of the determinant in the ``psi_det_sorted_bit`` array
END_DOC
implicit none
integer, intent(in) :: Nint
integer(bit_kind), intent(in) :: key(Nint,2)
integer :: i, ibegin, iend, istep, l
integer*8 :: det_ref, det_search
integer*8, external :: det_search_key
logical :: is_in_wavefunction
is_in_wavefunction = .False.
get_index_in_psi_det_sorted_bit = 0
ibegin = 1
iend = N_det+1
!DIR$ FORCEINLINE
det_ref = det_search_key(key,Nint)
!DIR$ FORCEINLINE
det_search = det_search_key(psi_det_sorted_bit(1,1,1),Nint)
istep = ishft(iend-ibegin,-1)
i=ibegin+istep
do while (istep > 0)
!DIR$ FORCEINLINE
det_search = det_search_key(psi_det_sorted_bit(1,1,i),Nint)
if ( det_search > det_ref ) then
iend = i
else if ( det_search == det_ref ) then
exit
else
ibegin = i
endif
istep = ishft(iend-ibegin,-1)
i = ibegin + istep
end do
!DIR$ FORCEINLINE
do while (det_search_key(psi_det_sorted_bit(1,1,i),Nint) == det_ref)
i = i-1
if (i == 0) then
exit
endif
enddo
i += 1
if (i > N_det) then
return
endif
!DIR$ FORCEINLINE
do while (det_search_key(psi_det_sorted_bit(1,1,i),Nint) == det_ref)
if ( (key(1,1) /= psi_det_sorted_bit(1,1,i)).or. &
(key(1,2) /= psi_det_sorted_bit(1,2,i)) ) then
continue
else
is_in_wavefunction = .True.
!DIR$ IVDEP
!DIR$ LOOP COUNT MIN(3)
do l=2,Nint
if ( (key(l,1) /= psi_det_sorted_bit(l,1,i)).or. &
(key(l,2) /= psi_det_sorted_bit(l,2,i)) ) then
is_in_wavefunction = .False.
endif
enddo
if (is_in_wavefunction) then
get_index_in_psi_det_sorted_bit = i
! exit
return
endif
endif
i += 1
if (i > N_det) then
! exit
return
endif
enddo
! DEBUG is_in_wf
! if (is_in_wavefunction) then
! degree = 1
! do i=1,N_det
! integer :: degree
! call get_excitation_degree(key,psi_det(1,1,i),degree,N_int)
! if (degree == 0) then
! exit
! endif
! enddo
! if (degree /=0) then
! stop 'pouet 1'
! endif
! else
! do i=1,N_det
! call get_excitation_degree(key,psi_det(1,1,i),degree,N_int)
! if (degree == 0) then
! stop 'pouet 2'
! endif
! enddo
! endif
! END DEBUG is_in_wf
end
integer function connected_to_ref(key,keys,Nint,N_past_in,Ndet)
use bitmasks
implicit none
integer, intent(in) :: Nint, N_past_in, Ndet
integer(bit_kind), intent(in) :: keys(Nint,2,Ndet)
integer(bit_kind), intent(in) :: key(Nint,2)
integer :: N_past
integer :: i, l
integer :: degree_x2
logical :: t
double precision :: hij_elec
! output : 0 : not connected
! i : connected to determinant i of the past
! -i : is the ith determinant of the refernce wf keys
ASSERT (Nint > 0)
ASSERT (Nint == N_int)
connected_to_ref = 0
N_past = max(1,N_past_in)
if (Nint == 1) then
do i=N_past-1,1,-1
degree_x2 = popcnt(xor( key(1,1), keys(1,1,i))) + &
popcnt(xor( key(1,2), keys(1,2,i)))
if (degree_x2 > 4) then
cycle
else
connected_to_ref = i
return
endif
enddo
return
else if (Nint==2) then
do i=N_past-1,1,-1
degree_x2 = popcnt(xor( key(1,1), keys(1,1,i))) + &
popcnt(xor( key(1,2), keys(1,2,i))) + &
popcnt(xor( key(2,1), keys(2,1,i))) + &
popcnt(xor( key(2,2), keys(2,2,i)))
if (degree_x2 > 4) then
cycle
else
connected_to_ref = i
return
endif
enddo
return
else if (Nint==3) then
do i=N_past-1,1,-1
degree_x2 = popcnt(xor( key(1,1), keys(1,1,i))) + &
popcnt(xor( key(1,2), keys(1,2,i))) + &
popcnt(xor( key(2,1), keys(2,1,i))) + &
popcnt(xor( key(2,2), keys(2,2,i))) + &
popcnt(xor( key(3,1), keys(3,1,i))) + &
popcnt(xor( key(3,2), keys(3,2,i)))
if (degree_x2 > 4) then
cycle
else
connected_to_ref = i
return
endif
enddo
return
else
do i=N_past-1,1,-1
degree_x2 = popcnt(xor( key(1,1), keys(1,1,i))) + &
popcnt(xor( key(1,2), keys(1,2,i)))
!DEC$ LOOP COUNT MIN(3)
do l=2,Nint
degree_x2 = degree_x2 + popcnt(xor( key(l,1), keys(l,1,i))) +&
popcnt(xor( key(l,2), keys(l,2,i)))
enddo
if (degree_x2 > 4) then
cycle
else
connected_to_ref = i
return
endif
enddo
endif
end
integer function connected_to_ref_by_mono(key,keys,Nint,N_past_in,Ndet)
use bitmasks
implicit none
integer, intent(in) :: Nint, N_past_in, Ndet
integer(bit_kind), intent(in) :: keys(Nint,2,Ndet)
integer(bit_kind), intent(in) :: key(Nint,2)
integer :: N_past
integer :: i, l
integer :: degree_x2
logical :: t
double precision :: hij_elec
! output : 0 : not connected
! i : connected to determinant i of the past
! -i : is the ith determinant of the refernce wf keys
ASSERT (Nint > 0)
ASSERT (Nint == N_int)
connected_to_ref_by_mono = 0
N_past = max(1,N_past_in)
if (Nint == 1) then
do i=N_past-1,1,-1
degree_x2 = popcnt(xor( key(1,1), keys(1,1,i))) + &
popcnt(xor( key(1,2), keys(1,2,i)))
if (degree_x2 > 3.and. degree_x2 <5) then
cycle
else if (degree_x2 == 4)then
cycle
else if(degree_x2 == 2)then
connected_to_ref_by_mono = i
return
endif
enddo
return
else if (Nint==2) then
do i=N_past-1,1,-1
degree_x2 = popcnt(xor( key(1,1), keys(1,1,i))) + &
popcnt(xor( key(1,2), keys(1,2,i))) + &
popcnt(xor( key(2,1), keys(2,1,i))) + &
popcnt(xor( key(2,2), keys(2,2,i)))
if (degree_x2 > 3.and. degree_x2 <5) then
cycle
else if (degree_x2 == 4)then
cycle
else if(degree_x2 == 2)then
connected_to_ref_by_mono = i
return
endif
enddo
return
else if (Nint==3) then
do i=N_past-1,1,-1
degree_x2 = popcnt(xor( key(1,1), keys(1,1,i))) + &
popcnt(xor( key(1,2), keys(1,2,i))) + &
popcnt(xor( key(2,1), keys(2,1,i))) + &
popcnt(xor( key(2,2), keys(2,2,i))) + &
popcnt(xor( key(3,1), keys(3,1,i))) + &
popcnt(xor( key(3,2), keys(3,2,i)))
if (degree_x2 > 3.and. degree_x2 <5) then
cycle
else if (degree_x2 == 4)then
cycle
else if(degree_x2 == 2)then
connected_to_ref_by_mono = i
return
endif
enddo
return
else
do i=N_past-1,1,-1
degree_x2 = popcnt(xor( key(1,1), keys(1,1,i))) + &
popcnt(xor( key(1,2), keys(1,2,i)))
!DEC$ LOOP COUNT MIN(3)
do l=2,Nint
degree_x2 = degree_x2 + popcnt(xor( key(l,1), keys(l,1,i))) +&
popcnt(xor( key(l,2), keys(l,2,i)))
enddo
if (degree_x2 > 3.and. degree_x2 <5) then
cycle
else if (degree_x2 == 4)then
cycle
else if(degree_x2 == 2)then
connected_to_ref_by_mono = i
return
endif
enddo
endif
end