9
1
mirror of https://github.com/QuantumPackage/qp2.git synced 2024-12-21 19:13:29 +01:00
qp2/src/tc_bi_ortho/h_biortho.irp.f
2023-02-07 17:07:49 +01:00

244 lines
5.2 KiB
Fortran
Raw Blame History

This file contains invisible Unicode characters

This file contains invisible Unicode characters that are indistinguishable to humans but may be processed differently by a computer. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

! --
subroutine hmat_bi_ortho(key_j, key_i, Nint, hmono, htwoe, htot)
BEGIN_DOC
!
! < key_j | H | key_i > where | key_j > is developed on the LEFT basis and | key_i > is developed on the RIGHT basis
!
END_DOC
use bitmasks
implicit none
integer, intent(in) :: Nint
integer(bit_kind), intent(in) :: key_i(Nint,2), key_j(Nint,2)
double precision, intent(out) :: hmono, htwoe, htot
integer :: degree
hmono = 0.d0
htwoe = 0.d0
htot = 0.d0
call get_excitation_degree(key_i, key_j, degree, Nint)
if(degree .gt. 2) return
if(degree == 0) then
call diag_hmat_bi_ortho(Nint, key_i, hmono, htwoe)
htot = htot + nuclear_repulsion
else if (degree == 1) then
call single_hmat_bi_ortho(Nint, key_j, key_i, hmono, htwoe)
else if(degree == 2) then
call double_hmat_bi_ortho(Nint, key_j, key_i, hmono, htwoe)
endif
htot += hmono + htwoe
return
end subroutine hmat_bi_ortho
! ---
subroutine diag_hmat_bi_ortho(Nint, key_i, hmono, htwoe)
use bitmasks
implicit none
integer, intent(in) :: Nint
integer(bit_kind), intent(in) :: key_i(Nint,2)
double precision, intent(out) :: hmono, htwoe
integer :: occ(Nint*bit_kind_size,2)
integer :: Ne(2), i, j, ii, jj, ispin, jspin
hmono = 0.d0
htwoe = 0.d0
call bitstring_to_list_ab(key_i, occ, Ne, Nint)
do ispin = 1, 2
do i = 1, Ne(ispin)
ii = occ(i,ispin)
hmono += mo_bi_ortho_one_e(ii,ii)
enddo
enddo
! alpha/beta two-body
ispin = 1
jspin = 2
do i = 1, Ne(ispin) ! electron 1
ii = occ(i,ispin)
do j = 1, Ne(jspin) ! electron 2
jj = occ(j,jspin)
htwoe += mo_bi_ortho_coul_e(jj,ii,jj,ii)
enddo
enddo
! alpha/alpha two-body
do i = 1, Ne(ispin)
ii = occ(i,ispin)
do j = i+1, Ne(ispin)
jj = occ(j,ispin)
htwoe += mo_bi_ortho_coul_e(ii,jj,ii,jj) - mo_bi_ortho_coul_e(ii,jj,jj,ii)
enddo
enddo
! beta/beta two-body
do i = 1, Ne(jspin)
ii = occ(i,jspin)
do j = i+1, Ne(jspin)
jj = occ(j,jspin)
htwoe += mo_bi_ortho_coul_e(ii,jj,ii,jj) - mo_bi_ortho_coul_e(ii,jj,jj,ii)
enddo
enddo
return
end subroutine diag_hmat_bi_ortho
! ---
subroutine single_hmat_bi_ortho(Nint, key_j, key_i, hmono, htwoe)
BEGIN_DOC
!
! < key_j | H | key_i > for single excitation
!
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
integer :: occ(Nint*bit_kind_size,2)
integer :: Ne(2), i, j, ii, ispin, jspin
integer :: degree,exc(0:2,2,2)
integer :: h1, p1, h2, p2, s1, s2
integer :: other_spin(2)
double precision :: phase
other_spin(1) = 2
other_spin(2) = 1
hmono = 0.d0
htwoe = 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)
hmono = mo_bi_ortho_one_e(p1,h1) * phase
! alpha/beta two-body
ispin = other_spin(s1)
if(s1 == 1) then
! single alpha
do i = 1, Ne(ispin) ! electron 2
ii = occ(i,ispin)
htwoe += mo_bi_ortho_coul_e(ii,p1,ii,h1)
enddo
else
! single beta
do i = 1, Ne(ispin) ! electron 1
ii = occ(i,ispin)
htwoe += mo_bi_ortho_coul_e(p1,ii,h1,ii)
enddo
endif
! same spin two-body
do i = 1, Ne(s1)
ii = occ(i,s1)
! ( h1 p1 |ii ii ) - ( h1 ii | p1 ii )
htwoe += mo_bi_ortho_coul_e(ii,p1,ii,h1) - mo_bi_ortho_coul_e(p1,ii,ii,h1)
enddo
htwoe *= phase
end subroutine single_hmat_bi_ortho
! ---
subroutine double_hmat_bi_ortho(Nint, key_j, key_i, hmono, htwoe)
BEGIN_DOC
!
! < key_j | H | key_i> for double excitation
!
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
integer :: occ(Nint*bit_kind_size,2)
integer :: Ne(2), i, j, ii, ispin, jspin
integer :: degree,exc(0:2,2,2)
integer :: h1, p1, h2, p2, s1, s2
integer :: other_spin(2)
double precision :: phase
other_spin(1) = 2
other_spin(2) = 1
call get_excitation_degree(key_i, key_j, degree, Nint)
hmono = 0.d0
htwoe = 0.d0
if(degree .ne. 2) then
return
endif
call bitstring_to_list_ab(key_i, occ, Ne, Nint)
call get_double_excitation(key_i, key_j, exc, phase, Nint)
call decode_exc(exc, 2, h1, p1, h2, p2, s1, s2)
if(s1 .ne. s2) then
htwoe = mo_bi_ortho_coul_e(p2,p1,h2,h1)
else
! same spin two-body
! direct terms exchange terms
htwoe = mo_bi_ortho_coul_e(p2,p1,h2,h1) - mo_bi_ortho_coul_e(p1,p2,h2,h1)
endif
htwoe *= phase
end subroutine double_hmat_bi_ortho
! ---