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QuantumPackage/plugins/local/slater_tc/slater_tc_opt_single.irp.f
2024-05-07 21:00:19 +02:00

763 lines
24 KiB
Fortran

! ---
subroutine single_htilde_mu_mat_fock_bi_ortho(Nint, key_j, key_i, hmono, htwoe, hthree, htot)
BEGIN_DOC
!
! <key_j |H_tilde | key_i> for single excitation ONLY FOR ONE- AND TWO-BODY TERMS
!!
!! WARNING !!
!
! Non hermitian !!
!
END_DOC
use bitmasks
implicit none
integer, intent(in) :: Nint
integer(bit_kind), intent(in) :: key_j(Nint,2), key_i(Nint,2)
double precision, intent(out) :: hmono, htwoe, hthree, htot
integer :: occ(Nint*bit_kind_size,2)
integer :: Ne(2), i, j, ii, jj, ispin, jspin, k, kk
integer :: degree,exc(0:2,2,2)
integer :: h1, p1, h2, p2, s1, s2
double precision :: get_mo_two_e_integral_tc_int, phase
double precision :: direct_int, exchange_int_12, exchange_int_23, exchange_int_13
integer :: other_spin(2)
integer(bit_kind) :: key_j_core(Nint,2), key_i_core(Nint,2)
other_spin(1) = 2
other_spin(2) = 1
hmono = 0.d0
htwoe = 0.d0
hthree = 0.d0
htot = 0.d0
call get_excitation_degree(key_i, key_j, degree, Nint)
if(degree .ne. 1) then
return
endif
call bitstring_to_list_ab(key_i, occ, Ne, Nint)
call get_single_excitation(key_i, key_j, exc, phase, Nint)
call decode_exc(exc, 1, h1, p1, h2, p2, s1, s2)
call get_single_excitation_from_fock_tc(Nint, key_i, key_j, h1, p1, s1, phase, hmono, htwoe, hthree, htot)
end
! ---
subroutine get_single_excitation_from_fock_tc(Nint, key_i, key_j, h, p, spin, phase, hmono, htwoe, hthree, htot)
use bitmasks
implicit none
integer, intent(in) :: Nint
integer, intent(in) :: h, p, spin
double precision, intent(in) :: phase
integer(bit_kind), intent(in) :: key_i(Nint,2), key_j(Nint,2)
double precision, intent(out) :: hmono, htwoe, hthree, htot
integer(bit_kind) :: differences(Nint,2)
integer(bit_kind) :: hole(Nint,2)
integer(bit_kind) :: partcl(Nint,2)
integer :: occ_hole(Nint*bit_kind_size,2)
integer :: occ_partcl(Nint*bit_kind_size,2)
integer :: n_occ_ab_hole(2),n_occ_ab_partcl(2)
integer :: i0,i
double precision :: buffer_c(mo_num),buffer_x(mo_num)
do i = 1, mo_num
buffer_c(i) = tc_2e_3idx_coulomb_integrals (i,p,h)
buffer_x(i) = tc_2e_3idx_exchange_integrals(i,p,h)
enddo
do i = 1, Nint
differences(i,1) = xor(key_i(i,1), ref_closed_shell_bitmask(i,1))
differences(i,2) = xor(key_i(i,2), ref_closed_shell_bitmask(i,2))
hole (i,1) = iand(differences(i,1), ref_closed_shell_bitmask(i,1))
hole (i,2) = iand(differences(i,2), ref_closed_shell_bitmask(i,2))
partcl (i,1) = iand(differences(i,1), key_i(i,1))
partcl (i,2) = iand(differences(i,2), key_i(i,2))
enddo
call bitstring_to_list_ab(hole, occ_hole, n_occ_ab_hole, Nint)
call bitstring_to_list_ab(partcl, occ_partcl, n_occ_ab_partcl, Nint)
hmono = mo_bi_ortho_tc_one_e(p,h)
htwoe = fock_op_2_e_tc_closed_shell(p,h)
! holes :: direct terms
do i0 = 1, n_occ_ab_hole(1)
i = occ_hole(i0,1)
htwoe -= buffer_c(i)
enddo
do i0 = 1, n_occ_ab_hole(2)
i = occ_hole(i0,2)
htwoe -= buffer_c(i)
enddo
! holes :: exchange terms
do i0 = 1, n_occ_ab_hole(spin)
i = occ_hole(i0,spin)
htwoe += buffer_x(i)
enddo
! particles :: direct terms
do i0 = 1, n_occ_ab_partcl(1)
i = occ_partcl(i0,1)
htwoe += buffer_c(i)
enddo
do i0 = 1, n_occ_ab_partcl(2)
i = occ_partcl(i0,2)
htwoe += buffer_c(i)
enddo
! particles :: exchange terms
do i0 = 1, n_occ_ab_partcl(spin)
i = occ_partcl(i0,spin)
htwoe -= buffer_x(i)
enddo
hthree = 0.d0
if (three_body_h_tc .and. elec_num.gt.2 .and. three_e_4_idx_term) then
call three_comp_fock_elem(Nint, key_i, h, p, spin, hthree)
endif
htwoe = htwoe * phase
hmono = hmono * phase
hthree = hthree * phase
htot = htwoe + hmono + hthree
end
! ---
subroutine three_comp_fock_elem(Nint, key_i, h_fock, p_fock, ispin_fock, hthree)
implicit none
integer, intent(in) :: Nint
integer, intent(in) :: h_fock, p_fock, ispin_fock
integer(bit_kind), intent(in) :: key_i(Nint,2)
double precision, intent(out) :: hthree
integer :: nexc(2),i,ispin,na,nb
integer(bit_kind) :: hole(Nint,2)
integer(bit_kind) :: particle(Nint,2)
integer :: occ_hole(Nint*bit_kind_size,2)
integer :: occ_particle(Nint*bit_kind_size,2)
integer :: n_occ_ab_hole(2),n_occ_ab_particle(2)
integer(bit_kind) :: det_tmp(Nint,2)
nexc(1) = 0
nexc(2) = 0
!! Get all the holes and particles of key_i with respect to the ROHF determinant
do i = 1, Nint
hole(i,1) = xor(key_i(i,1),ref_bitmask(i,1))
hole(i,2) = xor(key_i(i,2),ref_bitmask(i,2))
particle(i,1) = iand(hole(i,1),key_i(i,1))
particle(i,2) = iand(hole(i,2),key_i(i,2))
hole(i,1) = iand(hole(i,1),ref_bitmask(i,1))
hole(i,2) = iand(hole(i,2),ref_bitmask(i,2))
nexc(1) = nexc(1) + popcnt(hole(i,1))
nexc(2) = nexc(2) + popcnt(hole(i,2))
enddo
integer :: tmp(2)
!DIR$ FORCEINLINE
call bitstring_to_list_ab(particle, occ_particle, tmp, Nint)
ASSERT (tmp(1) == nexc(1)) ! Number of particles alpha
ASSERT (tmp(2) == nexc(2)) ! Number of particle beta
!DIR$ FORCEINLINE
call bitstring_to_list_ab(hole, occ_hole, tmp, Nint)
ASSERT (tmp(1) == nexc(1)) ! Number of holes alpha
ASSERT (tmp(2) == nexc(2)) ! Number of holes beta
!! Initialize the matrix element with the reference ROHF Slater determinant Fock element
if(ispin_fock==1)then
hthree = fock_a_tot_3e_bi_orth(p_fock,h_fock)
else
hthree = fock_b_tot_3e_bi_orth(p_fock,h_fock)
endif
det_tmp = ref_bitmask
do ispin=1,2
na = elec_num_tab(ispin)
nb = elec_num_tab(iand(ispin,1)+1)
do i = 1, nexc(ispin)
!DIR$ FORCEINLINE
call fock_ac_tc_operator( occ_particle(i,ispin), ispin, det_tmp, h_fock,p_fock, ispin_fock, hthree, Nint, na, nb)
!DIR$ FORCEINLINE
call fock_a_tc_operator ( occ_hole (i,ispin), ispin, det_tmp, h_fock,p_fock, ispin_fock, hthree, Nint, na, nb)
enddo
enddo
end
! ---
subroutine fock_ac_tc_operator(iorb,ispin,key, h_fock,p_fock, ispin_fock,hthree,Nint,na,nb)
use bitmasks
implicit none
BEGIN_DOC
! Routine that computes the contribution to the three-electron part of the Fock operator
!
! a^dagger_{p_fock} a_{h_fock} of spin ispin_fock
!
! on top of a determinant 'key' on which you ADD an electron of spin ispin in orbital iorb
!
! in output, the determinant key is changed by the ADDITION of that electron
!
! the output hthree is INCREMENTED
END_DOC
integer, intent(in) :: iorb, ispin, Nint, h_fock,p_fock, ispin_fock
integer, intent(inout) :: na, nb
integer(bit_kind), intent(inout) :: key(Nint,2)
double precision, intent(inout) :: hthree
integer :: occ(Nint*bit_kind_size,2)
integer :: other_spin
integer :: k,l,i,jj,j
double precision :: direct_int, exchange_int
if (iorb < 1) then
print *, irp_here, ': iorb < 1'
print *, iorb, mo_num
stop -1
endif
if (iorb > mo_num) then
print *, irp_here, ': iorb > mo_num'
print *, iorb, mo_num
stop -1
endif
ASSERT (ispin > 0)
ASSERT (ispin < 3)
ASSERT (Nint > 0)
integer :: tmp(2)
!DIR$ FORCEINLINE
call bitstring_to_list_ab(key, occ, tmp, Nint)
ASSERT (tmp(1) == elec_alpha_num)
ASSERT (tmp(2) == elec_beta_num)
k = shiftr(iorb-1,bit_kind_shift)+1
ASSERT (k >0)
l = iorb - shiftl(k-1,bit_kind_shift)-1
ASSERT (l >= 0)
key(k,ispin) = ibset(key(k,ispin),l)
other_spin = iand(ispin,1)+1
!! spin of other electrons == ispin
if(ispin == ispin_fock)then
!! in what follows :: jj == other electrons in the determinant
!! :: iorb == electron that has been added of spin ispin
!! :: p_fock, h_fock == hole particle of spin ispin_fock
!! jj = ispin = ispin_fock >> pure parallel spin
do j = 1, na
jj = occ(j,ispin)
hthree += three_e_single_parrallel_spin_prov(jj,iorb,p_fock,h_fock)
enddo
!! spin of jj == other spin than ispin AND ispin_fock
!! exchange between the iorb and (h_fock, p_fock)
do j = 1, nb
jj = occ(j,other_spin)
direct_int = three_e_4_idx_direct_bi_ort(jj,iorb,p_fock,h_fock) ! USES 4-IDX TENSOR
! TODO
! use transpose
exchange_int = three_e_4_idx_exch13_bi_ort(iorb,jj,p_fock,h_fock) ! USES 4-IDX TENSOR
hthree += direct_int - exchange_int
enddo
else !! ispin NE to ispin_fock
!! jj = ispin BUT NON EQUAL TO ispin_fock
!! exchange between the jj and iorb
do j = 1, na
jj = occ(j,ispin)
direct_int = three_e_4_idx_direct_bi_ort(jj,iorb,p_fock,h_fock) ! USES 4-IDX TENSOR
exchange_int = three_e_4_idx_exch23_bi_ort(jj,iorb,p_fock,h_fock) ! USES 4-IDX TENSOR
hthree += direct_int - exchange_int
enddo
!! jj = other_spin than ispin BUT jj == ispin_fock
!! exchange between jj and (h_fock,p_fock)
do j = 1, nb
jj = occ(j,other_spin)
direct_int = three_e_4_idx_direct_bi_ort(jj,iorb,p_fock,h_fock) ! USES 4-IDX TENSOR
exchange_int = three_e_4_idx_exch13_bi_ort(jj,iorb,p_fock,h_fock) ! USES 4-IDX TENSOR
hthree += direct_int - exchange_int
enddo
endif
na = na+1
end
subroutine fock_a_tc_operator(iorb,ispin,key, h_fock,p_fock, ispin_fock,hthree,Nint,na,nb)
use bitmasks
implicit none
BEGIN_DOC
! Routine that computes the contribution to the three-electron part of the Fock operator
!
! a^dagger_{p_fock} a_{h_fock} of spin ispin_fock
!
! on top of a determinant 'key' on which you REMOVE an electron of spin ispin in orbital iorb
!
! in output, the determinant key is changed by the REMOVAL of that electron
!
! the output hthree is INCREMENTED
END_DOC
integer, intent(in) :: iorb, ispin, Nint, h_fock,p_fock, ispin_fock
integer, intent(inout) :: na, nb
integer(bit_kind), intent(inout) :: key(Nint,2)
double precision, intent(inout) :: hthree
double precision :: direct_int, exchange_int
integer :: occ(Nint*bit_kind_size,2)
integer :: other_spin
integer :: k,l,i,jj,mm,j,m
integer :: tmp(2)
ASSERT (iorb > 0)
ASSERT (ispin > 0)
ASSERT (ispin < 3)
ASSERT (Nint > 0)
k = shiftr(iorb-1,bit_kind_shift)+1
ASSERT (k>0)
l = iorb - shiftl(k-1,bit_kind_shift)-1
key(k,ispin) = ibclr(key(k,ispin),l)
other_spin = iand(ispin,1)+1
!DIR$ FORCEINLINE
call bitstring_to_list_ab(key, occ, tmp, Nint)
na = na-1
!! spin of other electrons == ispin
if(ispin == ispin_fock)then
!! in what follows :: jj == other electrons in the determinant
!! :: iorb == electron that has been added of spin ispin
!! :: p_fock, h_fock == hole particle of spin ispin_fock
!! jj = ispin = ispin_fock >> pure parallel spin
do j = 1, na
jj = occ(j,ispin)
hthree -= three_e_single_parrallel_spin_prov(jj,iorb,p_fock,h_fock)
enddo
!! spin of jj == other spin than ispin AND ispin_fock
!! exchange between the iorb and (h_fock, p_fock)
do j = 1, nb
jj = occ(j,other_spin)
direct_int = three_e_4_idx_direct_bi_ort(jj,iorb,p_fock,h_fock) ! USES 4-IDX TENSOR
! TODO use transpose
exchange_int = three_e_4_idx_exch13_bi_ort(iorb,jj,p_fock,h_fock) ! USES 4-IDX TENSOR
hthree -= direct_int - exchange_int
enddo
else !! ispin NE to ispin_fock
!! jj = ispin BUT NON EQUAL TO ispin_fock
!! exchange between the jj and iorb
do j = 1, na
jj = occ(j,ispin)
direct_int = three_e_4_idx_direct_bi_ort(jj,iorb,p_fock,h_fock) ! USES 4-IDX TENSOR
exchange_int = three_e_4_idx_exch23_bi_ort(jj,iorb,p_fock,h_fock) ! USES 4-IDX TENSOR
hthree -= direct_int - exchange_int
enddo
!! jj = other_spin than ispin BUT jj == ispin_fock
!! exchange between jj and (h_fock,p_fock)
do j = 1, nb
jj = occ(j,other_spin)
direct_int = three_e_4_idx_direct_bi_ort(jj,iorb,p_fock,h_fock) ! USES 4-IDX TENSOR
exchange_int = three_e_4_idx_exch13_bi_ort(jj,iorb,p_fock,h_fock) ! USES 4-IDX TENSOR
hthree -= direct_int - exchange_int
enddo
endif
end
! ---
BEGIN_PROVIDER [double precision, fock_op_2_e_tc_closed_shell, (mo_num, mo_num)]
BEGIN_DOC
! Closed-shell part of the Fock operator for the TC operator
END_DOC
implicit none
PROVIDE N_int
integer :: h0,p0,h,p,k0,k,i
integer :: n_occ_ab(2)
integer :: occ(N_int*bit_kind_size,2)
integer :: n_occ_ab_virt(2)
integer :: occ_virt(N_int*bit_kind_size,2)
integer(bit_kind) :: key_test(N_int)
integer(bit_kind) :: key_virt(N_int,2)
double precision :: accu
fock_op_2_e_tc_closed_shell = -1000.d0
call bitstring_to_list_ab(ref_closed_shell_bitmask, occ, n_occ_ab, N_int)
do i = 1, N_int
key_virt(i,1) = full_ijkl_bitmask(i)
key_virt(i,2) = full_ijkl_bitmask(i)
key_virt(i,1) = xor(key_virt(i,1),ref_closed_shell_bitmask(i,1))
key_virt(i,2) = xor(key_virt(i,2),ref_closed_shell_bitmask(i,2))
enddo
call bitstring_to_list_ab(key_virt, occ_virt, n_occ_ab_virt, N_int)
! docc ---> virt single excitations
do h0 = 1, n_occ_ab(1)
h = occ(h0,1)
do p0 = 1, n_occ_ab_virt(1)
p = occ_virt(p0,1)
accu = 0.d0
do k0 = 1, n_occ_ab(1)
k = occ(k0,1)
accu += 2.d0 * tc_2e_3idx_coulomb_integrals(k,p,h) - tc_2e_3idx_exchange_integrals(k,p,h)
enddo
fock_op_2_e_tc_closed_shell(p,h) = accu
enddo
enddo
do h0 = 1, n_occ_ab_virt(1)
h = occ_virt(h0,1)
do p0 = 1, n_occ_ab(1)
p = occ(p0,1)
accu = 0.d0
do k0 = 1, n_occ_ab(1)
k = occ(k0,1)
accu += 2.d0 * tc_2e_3idx_coulomb_integrals(k,p,h) - tc_2e_3idx_exchange_integrals(k,p,h)
enddo
fock_op_2_e_tc_closed_shell(p,h) = accu
enddo
enddo
! virt ---> virt single excitations
do h0 = 1, n_occ_ab_virt(1)
h=occ_virt(h0,1)
do p0 = 1, n_occ_ab_virt(1)
p = occ_virt(p0,1)
accu = 0.d0
do k0 = 1, n_occ_ab(1)
k = occ(k0,1)
accu += 2.d0 * tc_2e_3idx_coulomb_integrals(k,p,h) - tc_2e_3idx_exchange_integrals(k,p,h)
enddo
fock_op_2_e_tc_closed_shell(p,h) = accu
enddo
enddo
do h0 = 1, n_occ_ab_virt(1)
h = occ_virt(h0,1)
do p0 = 1, n_occ_ab_virt(1)
p=occ_virt(p0,1)
accu = 0.d0
do k0 = 1, n_occ_ab(1)
k = occ(k0,1)
accu += 2.d0 * tc_2e_3idx_coulomb_integrals(k,p,h) - tc_2e_3idx_exchange_integrals(k,p,h)
enddo
fock_op_2_e_tc_closed_shell(p,h) = accu
enddo
enddo
! docc ---> docc single excitations
do h0 = 1, n_occ_ab(1)
h=occ(h0,1)
do p0 = 1, n_occ_ab(1)
p = occ(p0,1)
accu = 0.d0
do k0 = 1, n_occ_ab(1)
k = occ(k0,1)
accu += 2.d0 * tc_2e_3idx_coulomb_integrals(k,p,h) - tc_2e_3idx_exchange_integrals(k,p,h)
enddo
fock_op_2_e_tc_closed_shell(p,h) = accu
enddo
enddo
do h0 = 1, n_occ_ab(1)
h = occ(h0,1)
do p0 = 1, n_occ_ab(1)
p=occ(p0,1)
accu = 0.d0
do k0 = 1, n_occ_ab(1)
k = occ(k0,1)
accu += 2.d0 * tc_2e_3idx_coulomb_integrals(k,p,h) - tc_2e_3idx_exchange_integrals(k,p,h)
enddo
fock_op_2_e_tc_closed_shell(p,h) = accu
enddo
enddo
! do i = 1, mo_num
! write(*,'(100(F10.5,X))')fock_op_2_e_tc_closed_shell(:,i)
! enddo
END_PROVIDER
! ---
subroutine single_htilde_mu_mat_fock_bi_ortho_no_3e(Nint, key_j, key_i, htot)
BEGIN_DOC
! <key_j |H_tilde | key_i> for single excitation ONLY FOR ONE- AND TWO-BODY TERMS
!!
!! WARNING !!
!
! Non hermitian !!
END_DOC
use bitmasks
implicit none
integer, intent(in) :: Nint
integer(bit_kind), intent(in) :: key_j(Nint,2), key_i(Nint,2)
double precision, intent(out) :: htot
double precision :: hmono, htwoe
integer :: occ(Nint*bit_kind_size,2)
integer :: Ne(2), i, j, ii, jj, ispin, jspin, k, kk
integer :: degree,exc(0:2,2,2)
integer :: h1, p1, h2, p2, s1, s2
double precision :: get_mo_two_e_integral_tc_int, phase
double precision :: direct_int, exchange_int_12, exchange_int_23, exchange_int_13
integer :: other_spin(2)
integer(bit_kind) :: key_j_core(Nint,2), key_i_core(Nint,2)
other_spin(1) = 2
other_spin(2) = 1
hmono = 0.d0
htwoe = 0.d0
htot = 0.d0
call get_excitation_degree(key_i, key_j, degree, Nint)
if(degree.ne.1)then
return
endif
call bitstring_to_list_ab(key_i, occ, Ne, Nint)
call get_single_excitation(key_i, key_j, exc, phase, Nint)
call decode_exc(exc,1,h1,p1,h2,p2,s1,s2)
call get_single_excitation_from_fock_tc_no_3e(Nint, key_i, key_j, h1, p1, s1, phase, hmono, htwoe, htot)
end
! ---
subroutine get_single_excitation_from_fock_tc_no_3e(Nint, key_i, key_j, h, p, spin, phase, hmono, htwoe, htot)
use bitmasks
implicit none
integer, intent(in) :: Nint
integer, intent(in) :: h, p, spin
double precision, intent(in) :: phase
integer(bit_kind), intent(in) :: key_i(Nint,2), key_j(Nint,2)
double precision, intent(out) :: hmono,htwoe,htot
integer(bit_kind) :: differences(Nint,2)
integer(bit_kind) :: hole(Nint,2)
integer(bit_kind) :: partcl(Nint,2)
integer :: occ_hole(Nint*bit_kind_size,2)
integer :: occ_partcl(Nint*bit_kind_size,2)
integer :: n_occ_ab_hole(2),n_occ_ab_partcl(2)
integer :: i0,i
double precision :: buffer_c(mo_num), buffer_x(mo_num)
do i = 1, mo_num
buffer_c(i) = tc_2e_3idx_coulomb_integrals(i,p,h)
buffer_x(i) = tc_2e_3idx_exchange_integrals(i,p,h)
enddo
do i = 1, Nint
differences(i,1) = xor(key_i(i,1),ref_closed_shell_bitmask(i,1))
differences(i,2) = xor(key_i(i,2),ref_closed_shell_bitmask(i,2))
hole(i,1) = iand(differences(i,1),ref_closed_shell_bitmask(i,1))
hole(i,2) = iand(differences(i,2),ref_closed_shell_bitmask(i,2))
partcl(i,1) = iand(differences(i,1),key_i(i,1))
partcl(i,2) = iand(differences(i,2),key_i(i,2))
enddo
call bitstring_to_list_ab(hole, occ_hole, n_occ_ab_hole, Nint)
call bitstring_to_list_ab(partcl, occ_partcl, n_occ_ab_partcl, Nint)
hmono = mo_bi_ortho_tc_one_e(p,h)
htwoe = fock_op_2_e_tc_closed_shell(p,h)
! holes :: direct terms
do i0 = 1, n_occ_ab_hole(1)
i = occ_hole(i0,1)
htwoe -= buffer_c(i)
enddo
do i0 = 1, n_occ_ab_hole(2)
i = occ_hole(i0,2)
htwoe -= buffer_c(i)
enddo
! holes :: exchange terms
do i0 = 1, n_occ_ab_hole(spin)
i = occ_hole(i0,spin)
htwoe += buffer_x(i)
enddo
! particles :: direct terms
do i0 = 1, n_occ_ab_partcl(1)
i = occ_partcl(i0,1)
htwoe += buffer_c(i)
enddo
do i0 = 1, n_occ_ab_partcl(2)
i = occ_partcl(i0,2)
htwoe += buffer_c(i)
enddo
! particles :: exchange terms
do i0 = 1, n_occ_ab_partcl(spin)
i = occ_partcl(i0,spin)
htwoe -= buffer_x(i)
enddo
htwoe = htwoe * phase
hmono = hmono * phase
htot = htwoe + hmono
end
subroutine single_htilde_mu_mat_fock_bi_ortho_no_3e_both(Nint, key_j, key_i, hji,hij)
BEGIN_DOC
! <key_j |H_tilde | key_i> and <key_i |H_tilde | key_j> for single excitation ONLY FOR ONE- AND TWO-BODY TERMS
!!
!! WARNING !!
!
! Non hermitian !!
END_DOC
use bitmasks
implicit none
integer, intent(in) :: Nint
integer(bit_kind), intent(in) :: key_j(Nint,2), key_i(Nint,2)
double precision, intent(out) :: hji,hij
double precision :: hmono, htwoe
integer :: occ(Nint*bit_kind_size,2)
integer :: Ne(2), i, j, ii, jj, ispin, jspin, k, kk
integer :: degree,exc(0:2,2,2)
integer :: h1, p1, h2, p2, s1, s2
double precision :: get_mo_two_e_integral_tc_int, phase
double precision :: direct_int, exchange_int_12, exchange_int_23, exchange_int_13
integer :: other_spin(2)
integer(bit_kind) :: key_j_core(Nint,2), key_i_core(Nint,2)
other_spin(1) = 2
other_spin(2) = 1
hmono = 0.d0
htwoe = 0.d0
hji = 0.d0
hij = 0.d0
call get_excitation_degree(key_i, key_j, degree, Nint)
if(degree.ne.1)then
return
endif
call bitstring_to_list_ab(key_i, occ, Ne, Nint)
call get_single_excitation(key_i, key_j, exc, phase, Nint)
call decode_exc(exc,1,h1,p1,h2,p2,s1,s2)
call get_single_excitation_from_fock_tc_no_3e_both(Nint, key_i, key_j, h1, p1, s1, phase, hji,hij)
end
! ---
subroutine get_single_excitation_from_fock_tc_no_3e_both(Nint, key_i, key_j, h, p, spin, phase, hji,hij)
use bitmasks
implicit none
integer, intent(in) :: Nint
integer, intent(in) :: h, p, spin
double precision, intent(in) :: phase
integer(bit_kind), intent(in) :: key_i(Nint,2), key_j(Nint,2)
double precision, intent(out) :: hji,hij
double precision :: hmono_ji,htwoe_ji
double precision :: hmono_ij,htwoe_ij
integer(bit_kind) :: differences(Nint,2)
integer(bit_kind) :: hole(Nint,2)
integer(bit_kind) :: partcl(Nint,2)
integer :: occ_hole(Nint*bit_kind_size,2)
integer :: occ_partcl(Nint*bit_kind_size,2)
integer :: n_occ_ab_hole(2),n_occ_ab_partcl(2)
integer :: i0,i
double precision :: buffer_c_ji(mo_num), buffer_x_ji(mo_num)
double precision :: buffer_c_ij(mo_num), buffer_x_ij(mo_num)
do i = 1, mo_num
buffer_c_ji(i) = tc_2e_3idx_coulomb_integrals(i,p,h)
buffer_x_ji(i) = tc_2e_3idx_exchange_integrals(i,p,h)
buffer_c_ij(i) = tc_2e_3idx_coulomb_integrals_transp(i,p,h)
buffer_x_ij(i) = tc_2e_3idx_exchange_integrals_transp(i,p,h)
enddo
do i = 1, Nint
differences(i,1) = xor(key_i(i,1),ref_closed_shell_bitmask(i,1))
differences(i,2) = xor(key_i(i,2),ref_closed_shell_bitmask(i,2))
hole(i,1) = iand(differences(i,1),ref_closed_shell_bitmask(i,1))
hole(i,2) = iand(differences(i,2),ref_closed_shell_bitmask(i,2))
partcl(i,1) = iand(differences(i,1),key_i(i,1))
partcl(i,2) = iand(differences(i,2),key_i(i,2))
enddo
call bitstring_to_list_ab(hole, occ_hole, n_occ_ab_hole, Nint)
call bitstring_to_list_ab(partcl, occ_partcl, n_occ_ab_partcl, Nint)
hmono_ji = mo_bi_ortho_tc_one_e(p,h)
htwoe_ji = fock_op_2_e_tc_closed_shell(p,h)
hmono_ij = mo_bi_ortho_tc_one_e(h,p)
htwoe_ij = fock_op_2_e_tc_closed_shell(h,p)
! holes :: direct terms
do i0 = 1, n_occ_ab_hole(1)
i = occ_hole(i0,1)
htwoe_ji -= buffer_c_ji(i)
htwoe_ij -= buffer_c_ij(i)
enddo
do i0 = 1, n_occ_ab_hole(2)
i = occ_hole(i0,2)
htwoe_ji -= buffer_c_ji(i)
htwoe_ij -= buffer_c_ij(i)
enddo
! holes :: exchange terms
do i0 = 1, n_occ_ab_hole(spin)
i = occ_hole(i0,spin)
htwoe_ji += buffer_x_ji(i)
htwoe_ij += buffer_x_ij(i)
enddo
! particles :: direct terms
do i0 = 1, n_occ_ab_partcl(1)
i = occ_partcl(i0,1)
htwoe_ji += buffer_c_ji(i)
htwoe_ij += buffer_c_ij(i)
enddo
do i0 = 1, n_occ_ab_partcl(2)
i = occ_partcl(i0,2)
htwoe_ji += buffer_c_ji(i)
htwoe_ij += buffer_c_ij(i)
enddo
! particles :: exchange terms
do i0 = 1, n_occ_ab_partcl(spin)
i = occ_partcl(i0,spin)
htwoe_ji -= buffer_x_ji(i)
htwoe_ij -= buffer_x_ij(i)
enddo
htwoe_ji = htwoe_ji * phase
hmono_ji = hmono_ji * phase
hji = htwoe_ji + hmono_ji
htwoe_ij = htwoe_ij * phase
hmono_ij = hmono_ij * phase
hij = htwoe_ij + hmono_ij
end