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mirror of https://github.com/QuantumPackage/qp2.git synced 2024-07-13 14:34:30 +02:00
qp2/src/csf/create_excitations.irp.f

280 lines
7.8 KiB
Fortran

subroutine do_single_excitation_cfg(key_in,key_out,i_hole,i_particle,ok)
use bitmasks
implicit none
BEGIN_DOC
! Applies the single excitation operator to a configuration
! If the excitation is possible, ok is True
END_DOC
integer, intent(in) :: i_hole,i_particle
integer(bit_kind), intent(in) :: key_in(N_int,2)
logical , intent(out) :: ok
integer :: k,j,i
integer(bit_kind) :: mask
integer(bit_kind) :: key_out(N_int,2)
ASSERT (i_hole > 0)
ASSERT (i_particle <= mo_num)
ok = .True.
key_out(:,:) = key_in(:,:)
! hole
k = shiftr(i_hole-1,bit_kind_shift)+1
j = i_hole-shiftl(k-1,bit_kind_shift)-1
mask = ibset(0_bit_kind,j)
! Check if the position j is singly occupied
! 1 -> 0 (SOMO)
! 0 0 (DOMO)
if (iand(key_out(k,1),mask) /= 0_bit_kind) then
key_out(k,1) = ibclr(key_out(k,1),j)
! Check if the position j is doubly occupied
! 0 -> 1 (SOMO)
! 1 0 (DOMO)
else if (iand(key_out(k,2),mask) /= 0_bit_kind) then
key_out(k,1) = ibset(key_out(k,1),j)
key_out(k,2) = ibclr(key_out(k,2),j)
! The position j is unoccupied: Not OK
! 0 -> 0 (SOMO)
! 0 0 (DOMO)
else
ok =.False.
return
endif
! particle
k = shiftr(i_particle-1,bit_kind_shift)+1
j = i_particle-shiftl(k-1,bit_kind_shift)-1
mask = ibset(0_bit_kind,j)
! Check if the position j is singly occupied
! 1 -> 0 (SOMO)
! 0 1 (DOMO)
if (iand(key_out(k,1),mask) /= 0_bit_kind) then
key_out(k,1) = ibclr(key_out(k,1),j)
key_out(k,2) = ibset(key_out(k,2),j)
! Check if the position j is doubly occupied : Not OK
! 0 -> 1 (SOMO)
! 1 0 (DOMO)
else if (iand(key_out(k,2),mask) /= 0_bit_kind) then
ok = .False.
return
! Position at j is unoccupied
! 0 -> 0 (SOMO)
! 0 0 (DOMO)
else
key_out(k,1) = ibset(key_out(k,1),j)
endif
end
subroutine do_single_excitation_cfg_with_type(key_in,key_out,i_hole,i_particle,ex_type,ok)
use bitmasks
implicit none
BEGIN_DOC
! Applies the single excitation operator to a configuration
! Returns the type of excitation in ex_type
! where the following convention is used
! 1 = (SOMO -> SOMO) 1 change in Nsomo
! 2 = (DOMO -> VMO) 1 change in Nsomo
! 3 = (SOMO -> VMO) 0 change in Nsomo
! 4 = (DOMO -> SOMO) 0 change in Nsomo
! If the excitation is possible, ok is True
END_DOC
integer, intent(in) :: i_hole,i_particle
integer(bit_kind), intent(in) :: key_in(N_int,2)
integer , intent(out) :: ex_type
logical , intent(out) :: ok
integer :: k,j,i
integer(bit_kind) :: mask
integer(bit_kind) :: key_out(N_int,2)
logical :: isholeSOMO
logical :: isparticleSOMO
logical :: isholeDOMO
logical :: isparticleVMO
isholeSOMO = .False.
isholeDOMO = .False.
isparticleSOMO = .False.
isparticleVMO = .False.
ASSERT (i_hole > 0)
ASSERT (i_particle <= mo_num)
ok = .True.
key_out(:,:) = key_in(:,:)
! hole
k = shiftr(i_hole-1,bit_kind_shift)+1
j = i_hole-shiftl(k-1,bit_kind_shift)-1
mask = ibset(0_bit_kind,j)
! Check if the position j is singly occupied
! 1 -> 0 (SOMO)
! 0 0 (DOMO)
if (iand(key_out(k,1),mask) /= 0_bit_kind) then
key_out(k,1) = ibclr(key_out(k,1),j)
isholeSOMO = .True.
! Check if the position j is doubly occupied
! 0 -> 1 (SOMO)
! 1 0 (DOMO)
else if (iand(key_out(k,2),mask) /= 0_bit_kind) then
key_out(k,1) = ibset(key_out(k,1),j)
key_out(k,2) = ibclr(key_out(k,2),j)
isholeDOMO = .True.
! The position j is unoccupied: Not OK
! 0 -> 0 (SOMO)
! 0 0 (DOMO)
else
ok =.False.
return
endif
! particle
k = shiftr(i_particle-1,bit_kind_shift)+1
j = i_particle-shiftl(k-1,bit_kind_shift)-1
mask = ibset(0_bit_kind,j)
! Check if the position j is singly occupied
! 1 -> 0 (SOMO)
! 0 1 (DOMO)
if (iand(key_out(k,1),mask) /= 0_bit_kind) then
key_out(k,1) = ibclr(key_out(k,1),j)
key_out(k,2) = ibset(key_out(k,2),j)
isparticleSOMO = .True.
! Check if the position j is doubly occupied : Not OK
! 0 -> 1 (SOMO)
! 1 0 (DOMO)
else if (iand(key_out(k,2),mask) /= 0_bit_kind) then
ok = .False.
return
! Position at j is unoccupied
! 0 -> 0 (SOMO)
! 0 0 (DOMO)
else
key_out(k,1) = ibset(key_out(k,1),j)
isparticleVMO = .True.
endif
if(isholeSOMO) then
! two possibilities
! particle is SOMO or VMO
if(isparticleSOMO) then
! SOMO -> SOMO
ex_type = 1
else
! SOMO -> VMO
ex_type = 3
endif
else
! two possibilities
! particle is SOMO or VMO
if(isparticleSOMO) then
! DOMO -> SOMO
ex_type = 4
else
! DOMO -> VMO
ex_type = 2
endif
endif
end
subroutine generate_all_singles_cfg(cfg,singles,n_singles,Nint)
implicit none
use bitmasks
BEGIN_DOC
! Generate all single excitation wrt a configuration
!
! n_singles : on input, max number of singles :
! elec_alpha_num * (mo_num - elec_beta_num)
! on output, number of generated singles
END_DOC
integer, intent(in) :: Nint
integer, intent(inout) :: n_singles
integer(bit_kind), intent(in) :: cfg(Nint,2)
integer(bit_kind), intent(out) :: singles(Nint,2,*)
integer :: i,k, n_singles_ma, i_hole, i_particle
integer(bit_kind) :: single(Nint,2)
logical :: i_ok
n_singles = 0
!TODO
!Make list of Somo and Domo for holes
!Make list of Unocc and Somo for particles
do i_hole = 1, mo_num
do i_particle = 1, mo_num
call do_single_excitation_cfg(cfg,single,i_hole,i_particle,i_ok)
if (i_ok) then
n_singles = n_singles + 1
do k=1,Nint
singles(k,1,n_singles) = single(k,1)
singles(k,2,n_singles) = single(k,2)
enddo
endif
enddo
enddo
end
subroutine generate_all_singles_cfg_with_type(cfgInp,singles,idxs_singles,pq_singles,ex_type_singles,n_singles,Nint)
implicit none
use bitmasks
BEGIN_DOC
! Generate all single excitation wrt a configuration
!
! n_singles : on input, max number of singles :
! elec_alpha_num * (mo_num - elec_beta_num)
! on output, number of generated singles
! ex_type_singles : on output contains type of excitations :
!
END_DOC
integer, intent(in) :: Nint
integer, intent(inout) :: n_singles
integer, intent(out) :: idxs_singles(*)
integer, intent(out) :: ex_type_singles(*)
integer, intent(out) :: pq_singles(2,*)
integer(bit_kind), intent(in) :: cfgInp(Nint,2)
integer(bit_kind), intent(out) :: singles(Nint,2,*)
integer(bit_kind) :: Jdet(Nint,2)
integer :: i,k, n_singles_ma, i_hole, i_particle, ex_type, addcfg
integer(bit_kind) :: single(Nint,2)
logical :: i_ok
n_singles = 0
!TODO
!Make list of Somo and Domo for holes
!Make list of Unocc and Somo for particles
do i_hole = 1+n_core_orb, n_core_orb + n_act_orb
do i_particle = 1+n_core_orb, n_core_orb + n_act_orb
if(i_hole .EQ. i_particle) cycle
addcfg = -1
call do_single_excitation_cfg_with_type(cfgInp,single,i_hole,i_particle,ex_type,i_ok)
if (i_ok) then
call binary_search_cfg(single,addcfg)
if(addcfg .EQ. -1) cycle
n_singles = n_singles + 1
do k=1,Nint
singles(k,1,n_singles) = single(k,1)
singles(k,2,n_singles) = single(k,2)
ex_type_singles(n_singles) = ex_type
pq_singles(1,n_singles) = i_hole ! p
pq_singles(2,n_singles) = i_particle ! q
idxs_singles(n_singles) = addcfg
enddo
endif
enddo
enddo
end