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qp2/src/determinants/slater_rules_wee_mono.irp.f
2019-02-04 23:51:09 +01:00

364 lines
11 KiB
Fortran

subroutine i_Wee_j_single(key_i,key_j,Nint,spin,hij)
use bitmasks
implicit none
BEGIN_DOC
! Returns $\langle i|H|j \rangle$ where $i$ and $j$ are determinants differing by a
! single excitation.
END_DOC
integer, intent(in) :: Nint, spin
integer(bit_kind), intent(in) :: key_i(Nint,2), key_j(Nint,2)
double precision, intent(out) :: hij
integer :: exc(0:2,2)
double precision :: phase
PROVIDE big_array_exchange_integrals mo_two_e_integrals_in_map
call get_single_excitation_spin(key_i(1,spin),key_j(1,spin),exc,phase,Nint)
call single_excitation_wee(key_i,key_j,exc(1,1),exc(1,2),spin,phase,hij)
end
double precision function diag_wee_mat_elem(det_in,Nint)
implicit none
BEGIN_DOC
! Computes $\langle i|H|i \rangle$.
END_DOC
integer,intent(in) :: Nint
integer(bit_kind),intent(in) :: det_in(Nint,2)
integer(bit_kind) :: hole(Nint,2)
integer(bit_kind) :: particle(Nint,2)
integer :: i, nexc(2), ispin
integer :: occ_particle(Nint*bit_kind_size,2)
integer :: occ_hole(Nint*bit_kind_size,2)
integer(bit_kind) :: det_tmp(Nint,2)
integer :: na, nb
ASSERT (Nint > 0)
ASSERT (sum(popcnt(det_in(:,1))) == elec_alpha_num)
ASSERT (sum(popcnt(det_in(:,2))) == elec_beta_num)
nexc(1) = 0
nexc(2) = 0
do i=1,Nint
hole(i,1) = xor(det_in(i,1),ref_bitmask(i,1))
hole(i,2) = xor(det_in(i,2),ref_bitmask(i,2))
particle(i,1) = iand(hole(i,1),det_in(i,1))
particle(i,2) = iand(hole(i,2),det_in(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
diag_wee_mat_elem = ref_bitmask_two_e_energy
if (nexc(1)+nexc(2) == 0) then
return
endif
!call debug_det(det_in,Nint)
integer :: tmp(2)
!DIR$ FORCEINLINE
call bitstring_to_list_ab(particle, occ_particle, tmp, Nint)
ASSERT (tmp(1) == nexc(1))
ASSERT (tmp(2) == nexc(2))
!DIR$ FORCEINLINE
call bitstring_to_list_ab(hole, occ_hole, tmp, Nint)
ASSERT (tmp(1) == nexc(1))
ASSERT (tmp(2) == nexc(2))
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 ac_operator_two_e( occ_particle(i,ispin), ispin, det_tmp, diag_wee_mat_elem, Nint,na,nb)
!DIR$ FORCEINLINE
call a_operator_two_e ( occ_hole (i,ispin), ispin, det_tmp, diag_wee_mat_elem, Nint,na,nb)
enddo
enddo
end
subroutine a_operator_two_e(iorb,ispin,key,hjj,Nint,na,nb)
use bitmasks
implicit none
BEGIN_DOC
! Needed for :c:func:`diag_Wee_mat_elem`.
END_DOC
integer, intent(in) :: iorb, ispin, Nint
integer, intent(inout) :: na, nb
integer(bit_kind), intent(inout) :: key(Nint,2)
double precision, intent(inout) :: hjj
integer :: occ(Nint*bit_kind_size,2)
integer :: other_spin
integer :: k,l,i
integer :: tmp(2)
ASSERT (iorb > 0)
ASSERT (ispin > 0)
ASSERT (ispin < 3)
ASSERT (Nint > 0)
k = ishft(iorb-1,-bit_kind_shift)+1
ASSERT (k > 0)
l = iorb - ishft(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
! Same spin
do i=1,na
hjj = hjj - mo_two_e_integrals_jj_anti(occ(i,ispin),iorb)
enddo
! Opposite spin
do i=1,nb
hjj = hjj - mo_two_e_integrals_jj(occ(i,other_spin),iorb)
enddo
end
subroutine ac_operator_two_e(iorb,ispin,key,hjj,Nint,na,nb)
use bitmasks
implicit none
BEGIN_DOC
! Needed for :c:func:`diag_Wee_mat_elem`.
END_DOC
integer, intent(in) :: iorb, ispin, Nint
integer, intent(inout) :: na, nb
integer(bit_kind), intent(inout) :: key(Nint,2)
double precision, intent(inout) :: hjj
integer :: occ(Nint*bit_kind_size,2)
integer :: other_spin
integer :: k,l,i
ASSERT (iorb > 0)
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 = ishft(iorb-1,-bit_kind_shift)+1
ASSERT (k > 0)
l = iorb - ishft(k-1,bit_kind_shift)-1
key(k,ispin) = ibset(key(k,ispin),l)
other_spin = iand(ispin,1)+1
! Same spin
do i=1,na
hjj = hjj + mo_two_e_integrals_jj_anti(occ(i,ispin),iorb)
enddo
! Opposite spin
do i=1,nb
hjj = hjj + mo_two_e_integrals_jj(occ(i,other_spin),iorb)
enddo
na = na+1
end
subroutine i_H_j_mono_spin_one_e(key_i,key_j,Nint,spin,hij)
use bitmasks
implicit none
BEGIN_DOC
! Returns $\langle i|H|j \rangle$ where $i$ and $j$ are determinants differing by
! a single excitation.
END_DOC
integer, intent(in) :: Nint, spin
integer(bit_kind), intent(in) :: key_i(Nint,2), key_j(Nint,2)
double precision, intent(out) :: hij
integer :: exc(0:2,2)
double precision :: phase
call get_single_excitation_spin(key_i(1,spin),key_j(1,spin),exc,phase,Nint)
integer :: m,p
m = exc(1,1)
p = exc(1,2)
hij = phase * mo_one_e_integrals(m,p)
end
double precision function diag_H_mat_elem_one_e(det_in,Nint)
use bitmasks
implicit none
BEGIN_DOC
! Computes $\langle i|H|i \rangle$.
END_DOC
integer,intent(in) :: Nint
integer(bit_kind),intent(in) :: det_in(Nint,2)
integer(bit_kind) :: hole(Nint,2)
integer(bit_kind) :: particle(Nint,2)
integer :: i, nexc(2), ispin
integer :: occ_particle(Nint*bit_kind_size,2)
integer :: occ_hole(Nint*bit_kind_size,2)
integer(bit_kind) :: det_tmp(Nint,2)
integer :: na, nb
ASSERT (Nint > 0)
ASSERT (sum(popcnt(det_in(:,1))) == elec_alpha_num)
ASSERT (sum(popcnt(det_in(:,2))) == elec_beta_num)
diag_H_mat_elem_one_e = 0.d0
!call debug_det(det_in,Nint)
integer :: tmp(2)
!DIR$ FORCEINLINE
call bitstring_to_list_ab(det_in, occ_particle, tmp, Nint)
do ispin = 1,2
do i = 1, tmp(ispin)
diag_H_mat_elem_one_e += mo_one_e_integrals(occ_particle(i,ispin),occ_particle(i,ispin))
enddo
enddo
end
subroutine i_H_j_one_e(key_i,key_j,Nint,hij)
use bitmasks
implicit none
BEGIN_DOC
! Returns $\langle i|H|j \rangle$ where $i$ and $j$ are determinants.
END_DOC
integer, intent(in) :: Nint
integer(bit_kind), intent(in) :: key_i(Nint,2), key_j(Nint,2)
double precision, intent(out) :: hij
integer :: degree,m,p
double precision :: diag_H_mat_elem_one_e,phase
integer :: exc(0:2,2,2)
call get_excitation_degree(key_i,key_j,degree,Nint)
hij = 0.d0
if(degree>1)then
return
endif
if(degree==0)then
hij = diag_H_mat_elem_one_e(key_i,N_int)
else
call get_single_excitation(key_i,key_j,exc,phase,Nint)
if (exc(0,1,1) == 1) then
! Mono alpha
m = exc(1,1,1)
p = exc(1,2,1)
else
! Mono beta
m = exc(1,1,2)
p = exc(1,2,2)
endif
hij = phase * mo_one_e_integrals(m,p)
endif
end
subroutine i_H_j_two_e(key_i,key_j,Nint,hij)
use bitmasks
implicit none
BEGIN_DOC
! Returns $\langle i|H|j \rangle$ where $i$ and $j$ are determinants.
END_DOC
integer, intent(in) :: Nint
integer(bit_kind), intent(in) :: key_i(Nint,2), key_j(Nint,2)
double precision, intent(out) :: hij
integer :: exc(0:2,2,2)
integer :: degree
double precision :: get_two_e_integral
integer :: m,n,p,q
integer :: i,j,k
integer :: occ(Nint*bit_kind_size,2)
double precision :: diag_H_mat_elem, phase,phase_2
integer :: n_occ_ab(2)
PROVIDE mo_two_e_integrals_in_map mo_integrals_map big_array_exchange_integrals ref_bitmask_two_e_energy
ASSERT (Nint > 0)
ASSERT (Nint == N_int)
ASSERT (sum(popcnt(key_i(:,1))) == elec_alpha_num)
ASSERT (sum(popcnt(key_i(:,2))) == elec_beta_num)
ASSERT (sum(popcnt(key_j(:,1))) == elec_alpha_num)
ASSERT (sum(popcnt(key_j(:,2))) == elec_beta_num)
hij = 0.d0
!DIR$ FORCEINLINE
call get_excitation_degree(key_i,key_j,degree,Nint)
integer :: spin
select case (degree)
case (2)
call get_double_excitation(key_i,key_j,exc,phase,Nint)
if (exc(0,1,1) == 1) then
! Mono alpha, mono beta
if(exc(1,1,1) == exc(1,2,2) )then
hij = phase * big_array_exchange_integrals(exc(1,1,1),exc(1,1,2),exc(1,2,1))
else if (exc(1,2,1) ==exc(1,1,2))then
hij = phase * big_array_exchange_integrals(exc(1,2,1),exc(1,1,1),exc(1,2,2))
else
hij = phase*get_two_e_integral( &
exc(1,1,1), &
exc(1,1,2), &
exc(1,2,1), &
exc(1,2,2) ,mo_integrals_map)
endif
else if (exc(0,1,1) == 2) then
! Double alpha
hij = phase*(get_two_e_integral( &
exc(1,1,1), &
exc(2,1,1), &
exc(1,2,1), &
exc(2,2,1) ,mo_integrals_map) - &
get_two_e_integral( &
exc(1,1,1), &
exc(2,1,1), &
exc(2,2,1), &
exc(1,2,1) ,mo_integrals_map) )
else if (exc(0,1,2) == 2) then
! Double beta
hij = phase*(get_two_e_integral( &
exc(1,1,2), &
exc(2,1,2), &
exc(1,2,2), &
exc(2,2,2) ,mo_integrals_map) - &
get_two_e_integral( &
exc(1,1,2), &
exc(2,1,2), &
exc(2,2,2), &
exc(1,2,2) ,mo_integrals_map) )
endif
case (1)
call get_single_excitation(key_i,key_j,exc,phase,Nint)
!DIR$ FORCEINLINE
call bitstring_to_list_ab(key_i, occ, n_occ_ab, Nint)
if (exc(0,1,1) == 1) then
! Mono alpha
m = exc(1,1,1)
p = exc(1,2,1)
spin = 1
else
! Mono beta
m = exc(1,1,2)
p = exc(1,2,2)
spin = 2
endif
call single_excitation_wee(key_i,key_j,p,m,spin,phase,hij)
case (0)
double precision :: diag_wee_mat_elem
hij = diag_wee_mat_elem(key_i,Nint)
end select
end