9
1
mirror of https://github.com/QuantumPackage/qp2.git synced 2024-10-11 02:11:30 +02:00
qp2/plugins/local/tc_bi_ortho/two_rdm_naive.irp.f

167 lines
5.5 KiB
Fortran

BEGIN_PROVIDER [ double precision, tc_two_rdm_chemist, (mo_num, mo_num, mo_num, mo_num)]
&BEGIN_PROVIDER [ double precision, tc_two_rdm_chemist_s1s2, (mo_num, mo_num, mo_num, mo_num, 2,2)]
implicit none
BEGIN_DOC
! tc_two_rdm_chemist(p,s,q,r) = <Phi| a^dagger_p a^dagger_q q_r a_s |Phi> = CHEMIST NOTATION
END_DOC
integer :: i,j,istate,m,mm,nn
integer :: exc(0:2,2,2)
double precision :: phase
double precision :: contrib
integer :: h1,p1,s1,h2,p2,s2,degree
integer, allocatable :: occ(:,:)
integer :: n_occ_ab(2),other_spin(2)
other_spin(1) = 2
other_spin(2) = 1
allocate(occ(N_int*bit_kind_size,2))
tc_two_rdm_chemist = 0.d0
tc_two_rdm_chemist_s1s2 = 0.d0
do i = 1, N_det ! psi_left
do j = 1, N_det ! psi_right
call get_excitation_degree(psi_det(1,1,i),psi_det(1,1,j),degree,N_int)
if(degree.gt.2)cycle
if(degree.gt.0)then
! get excitation operators: from psi_det(j) --> psi_det(i)
! T_{j-->i} = a^p1_s1 a_h1_s1
call get_excitation(psi_det(1,1,j),psi_det(1,1,i),exc,degree,phase,N_int)
call decode_exc(exc,degree,h1,p1,h2,p2,s1,s2)
contrib = psi_l_coef_bi_ortho(i,1) * psi_r_coef_bi_ortho(j,1) * phase * state_average_weight(1)
do istate = 2, N_states
contrib += psi_l_coef_bi_ortho(i,istate) * psi_r_coef_bi_ortho(j,istate) * phase * state_average_weight(istate)
enddo
if(degree == 2)then
call update_tc_rdm(h1,p1,h2,p2,s1,s2,tc_two_rdm_chemist,mo_num,contrib)
call update_tc_rdm(h1,p1,h2,p2,s1,s2,tc_two_rdm_chemist_s1s2(1,1,1,1,s1,s2) ,mo_num,contrib)
else if(degree==1)then
! occupation of the determinant psi_det(j)
call bitstring_to_list_ab(psi_det(1,1,j), occ, n_occ_ab, N_int)
! run over the electrons of opposite spin than the excitation
s2 = other_spin(s1)
do mm = 1, n_occ_ab(s2)
m = occ(mm,s2)
h2 = m
p2 = m
call update_tc_rdm(h1,p1,h2,p2,s1,s2,tc_two_rdm_chemist,mo_num,contrib)
call update_tc_rdm(h1,p1,h2,p2,s1,s2,tc_two_rdm_chemist_s1s2(1,1,1,1,s1,s2) ,mo_num,contrib)
enddo
! run over the electrons of same spin than the excitation
s2 = s1
do mm = 1, n_occ_ab(s2)
m = occ(mm,s2)
h2 = m
p2 = m
call update_tc_rdm(h1,p1,h2,p2,s1,s2,tc_two_rdm_chemist,mo_num,contrib)
call update_tc_rdm(h1,p1,h2,p2,s1,s2,tc_two_rdm_chemist_s1s2(1,1,1,1,s1,s2) ,mo_num,contrib)
enddo
endif
else if(degree == 0)then
! cycle
contrib = psi_l_coef_bi_ortho(i,1) * psi_r_coef_bi_ortho(j,1) * state_average_weight(1)
do istate = 2, N_states
contrib += psi_l_coef_bi_ortho(i,istate) * psi_r_coef_bi_ortho(j,istate) * state_average_weight(istate)
enddo
! occupation of the determinant psi_det(j)
call bitstring_to_list_ab(psi_det(1,1,j), occ, n_occ_ab, N_int)
s1 = 1 ! alpha electrons
do nn = 1, n_occ_ab(s1)
h1 = occ(nn,s1)
p1 = occ(nn,s1)
! run over the couple of alpha-beta electrons
s2 = other_spin(s1)
do mm = 1, n_occ_ab(s2)
m = occ(mm,s2)
h2 = m
p2 = m
call update_tc_rdm(h1,p1,h2,p2,s1,s2,tc_two_rdm_chemist,mo_num,contrib)
call update_tc_rdm(h1,p1,h2,p2,s1,s2,tc_two_rdm_chemist_s1s2(1,1,1,1,s1,s2) ,mo_num,contrib)
enddo
! run over the couple of alpha-alpha electrons
s2 = s1
do mm = 1, n_occ_ab(s2)
m = occ(mm,s2)
h2 = m
p2 = m
if(h2.le.h1)cycle
call update_tc_rdm(h1,p1,h2,p2,s1,s2,tc_two_rdm_chemist,mo_num,contrib)
call update_tc_rdm(h1,p1,h2,p2,s1,s2,tc_two_rdm_chemist_s1s2(1,1,1,1,s1,s2) ,mo_num,contrib)
enddo
enddo
s1 = 2
do nn = 1, n_occ_ab(s1)
h1 = occ(nn,s1)
p1 = occ(nn,s1)
! run over the couple of beta-beta electrons
s2 = s1
do mm = 1, n_occ_ab(s2)
m = occ(mm,s2)
h2 = m
p2 = m
if(h2.le.h1)cycle
call update_tc_rdm(h1,p1,h2,p2,s1,s2,tc_two_rdm_chemist,mo_num,contrib)
call update_tc_rdm(h1,p1,h2,p2,s1,s2,tc_two_rdm_chemist_s1s2(1,1,1,1,s1,s2) ,mo_num,contrib)
enddo
enddo
endif
enddo
enddo
END_PROVIDER
subroutine update_tc_rdm(h1,p1,h2,p2,s1,s2,array,sze,contrib)
implicit none
integer, intent(in) :: h1,p1,h2,p2,s1,s2,sze
double precision, intent(in) :: contrib
double precision, intent(inout) :: array(sze, sze, sze, sze)
integer :: istate
if(s1.ne.s2)then
array(p1,h1,p2,h2) += contrib
! permutation for particle symmetry
array(p2,h2,p1,h1) += contrib
else ! same spin double excitation
array(p1,h1,p2,h2) += contrib
! exchange
! exchanging the particles
array(p2,h1,p1,h2) -= contrib
! exchanging the
array(p1,h2,p2,h1) -= contrib
! permutation for particle symmetry
array(p2,h2,p1,h1) += contrib
endif
end
BEGIN_PROVIDER [ double precision, tc_two_rdm, (mo_num, mo_num, mo_num, mo_num)]
&BEGIN_PROVIDER [ double precision, tc_two_rdm_s1s2, (mo_num, mo_num, mo_num, mo_num,2,2)]
implicit none
BEGIN_DOC
! tc_two_rdm(p,q,s,r) = <Phi| a^dagger_p a^dagger_q q_r a_s |Phi> = PHYSICIST NOTATION
END_DOC
integer :: p,q,r,s,s1,s2
do r = 1, mo_num
do q = 1, mo_num
do s = 1, mo_num
do p = 1, mo_num
tc_two_rdm(p,q,s,r) = tc_two_rdm_chemist(p,s,q,r)
enddo
enddo
enddo
enddo
do s2 = 1, 2
do s1 = 1, 2
do r = 1, mo_num
do q = 1, mo_num
do s = 1, mo_num
do p = 1, mo_num
tc_two_rdm_s1s2(p,q,s,r,s1,s2) = tc_two_rdm_chemist_s1s2(p,s,q,r,s1,s2)
enddo
enddo
enddo
enddo
enddo
enddo
END_PROVIDER