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qp2/src/determinants/single_excitations.irp.f
2019-11-18 20:06:05 +01:00

162 lines
5.1 KiB
Fortran

use bitmasks
BEGIN_PROVIDER [integer(bit_kind), ref_closed_shell_bitmask, (N_int,2)]
implicit none
integer :: i,i0
integer :: n_occ_ab(2)
integer :: occ(N_int*bit_kind_size,2)
call bitstring_to_list_ab(ref_bitmask, occ, n_occ_ab, N_int)
! do the closed shell determinant
do i = 1, N_int
ref_closed_shell_bitmask(i,1) = ref_bitmask(i,1)
ref_closed_shell_bitmask(i,2) = ref_bitmask(i,2)
enddo
do i0 = elec_beta_num+1, elec_alpha_num
i=occ(i0,1)
call clear_bit_to_integer(i,ref_closed_shell_bitmask(1,1),N_int)
enddo
END_PROVIDER
BEGIN_PROVIDER [double precision, fock_operator_closed_shell_ref_bitmask, (mo_num, mo_num) ]
implicit none
integer :: i0,j0,i,j,k0,k
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)
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
double precision, allocatable :: array_coulomb(:),array_exchange(:)
allocate (array_coulomb(mo_num),array_exchange(mo_num))
call bitstring_to_list_ab(key_virt, occ_virt, n_occ_ab_virt, N_int)
! docc ---> virt single excitations
do i0 = 1, n_occ_ab(1)
i=occ(i0,1)
do j0 = 1, n_occ_ab_virt(1)
j = occ_virt(j0,1)
call get_mo_two_e_integrals_coulomb_ii(i,j,mo_num,array_coulomb,mo_integrals_map)
call get_mo_two_e_integrals_exch_ii(i,j,mo_num,array_exchange,mo_integrals_map)
double precision :: accu
accu = 0.d0
do k0 = 1, n_occ_ab(1)
k = occ(k0,1)
accu += 2.d0 * array_coulomb(k) - array_exchange(k)
enddo
fock_operator_closed_shell_ref_bitmask(i,j) = accu + mo_one_e_integrals(i,j)
fock_operator_closed_shell_ref_bitmask(j,i) = accu + mo_one_e_integrals(i,j)
enddo
enddo
! virt ---> virt single excitations
do i0 = 1, n_occ_ab_virt(1)
i=occ_virt(i0,1)
do j0 = 1, n_occ_ab_virt(1)
j = occ_virt(j0,1)
call get_mo_two_e_integrals_coulomb_ii(i,j,mo_num,array_coulomb,mo_integrals_map)
call get_mo_two_e_integrals_exch_ii(i,j,mo_num,array_exchange,mo_integrals_map)
accu = 0.d0
do k0 = 1, n_occ_ab(1)
k = occ(k0,1)
accu += 2.d0 * array_coulomb(k) - array_exchange(k)
enddo
fock_operator_closed_shell_ref_bitmask(i,j) = accu+ mo_one_e_integrals(i,j)
fock_operator_closed_shell_ref_bitmask(j,i) = accu+ mo_one_e_integrals(i,j)
enddo
enddo
! docc ---> docc single excitations
do i0 = 1, n_occ_ab(1)
i=occ(i0,1)
do j0 = 1, n_occ_ab(1)
j = occ(j0,1)
call get_mo_two_e_integrals_coulomb_ii(i,j,mo_num,array_coulomb,mo_integrals_map)
call get_mo_two_e_integrals_exch_ii(i,j,mo_num,array_exchange,mo_integrals_map)
accu = 0.d0
do k0 = 1, n_occ_ab(1)
k = occ(k0,1)
accu += 2.d0 * array_coulomb(k) - array_exchange(k)
enddo
fock_operator_closed_shell_ref_bitmask(i,j) = accu+ mo_one_e_integrals(i,j)
fock_operator_closed_shell_ref_bitmask(j,i) = accu+ mo_one_e_integrals(i,j)
enddo
enddo
deallocate(array_coulomb,array_exchange)
END_PROVIDER
subroutine get_single_excitation_from_fock(det_1,det_2,h,p,spin,phase,hij)
use bitmasks
implicit none
integer,intent(in) :: h,p,spin
double precision, intent(in) :: phase
integer(bit_kind), intent(in) :: det_1(N_int,2), det_2(N_int,2)
double precision, intent(out) :: hij
integer(bit_kind) :: differences(N_int,2)
integer(bit_kind) :: hole(N_int,2)
integer(bit_kind) :: partcl(N_int,2)
integer :: occ_hole(N_int*bit_kind_size,2)
integer :: occ_partcl(N_int*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) = big_array_coulomb_integrals(i,h,p)
buffer_x(i) = big_array_exchange_integrals(i,h,p)
enddo
do i = 1, N_int
differences(i,1) = xor(det_1(i,1),ref_closed_shell_bitmask(i,1))
differences(i,2) = xor(det_1(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),det_1(i,1))
partcl(i,2) = iand(differences(i,2),det_1(i,2))
enddo
call bitstring_to_list_ab(hole, occ_hole, n_occ_ab_hole, N_int)
call bitstring_to_list_ab(partcl, occ_partcl, n_occ_ab_partcl, N_int)
hij = fock_operator_closed_shell_ref_bitmask(h,p)
! holes :: direct terms
do i0 = 1, n_occ_ab_hole(1)
i = occ_hole(i0,1)
hij -= buffer_c(i)
enddo
do i0 = 1, n_occ_ab_hole(2)
i = occ_hole(i0,2)
hij -= buffer_c(i)
enddo
! holes :: exchange terms
do i0 = 1, n_occ_ab_hole(spin)
i = occ_hole(i0,spin)
hij += buffer_x(i)
enddo
! particles :: direct terms
do i0 = 1, n_occ_ab_partcl(1)
i = occ_partcl(i0,1)
hij += buffer_c(i)
enddo
do i0 = 1, n_occ_ab_partcl(2)
i = occ_partcl(i0,2)
hij += buffer_c(i)
enddo
! particles :: exchange terms
do i0 = 1, n_occ_ab_partcl(spin)
i = occ_partcl(i0,spin)
hij -= buffer_x(i)
enddo
hij = hij * phase
end