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mirror of https://github.com/pfloos/quack synced 2024-11-07 14:43:58 +01:00
quack/src/IntPak/VRR3e.f90

175 lines
7.6 KiB
Fortran

recursive function VRR3e(m,AngMomBra,maxm,Om,ExpZ,CenterZA,DY0,DY1,D2Y0,D2Y1) &
result(a1a2a3)
! Vertical recurrence relations for three-electron integrals
implicit none
include 'parameters.h'
! Input variables
integer,intent(in) :: m
integer,intent(in) :: AngMomBra(3,3)
integer,intent(in) :: maxm
double precision,intent(in) :: Om(0:maxm),ExpZ(3),CenterZA(3,3)
double precision,intent(in) :: DY0(3),DY1(3),D2Y0(3,3),D2Y1(3,3)
! Local variables
logical :: NegAngMomBra(3)
integer :: TotAngMomBra(3)
integer :: a1m(3,3),a2m(3,3),a3m(3,3)
integer :: a1mm(3,3),a2mm(3,3),a3mm(3,3)
integer :: a1m2m(3,3),a1m3m(3,3),a2m3m(3,3)
integer :: i,j,xyz
! Output variables
double precision :: a1a2a3
do i=1,3
NegAngMomBra(i) = AngMomBra(i,1) < 0 .or. AngMomBra(i,2) < 0 .or. AngMomBra(i,3) < 0
TotAngMomBra(i) = AngMomBra(i,1) + AngMomBra(i,2) + AngMomBra(i,3)
end do
!------------------------------------------------------------------------
! Termination condition
!------------------------------------------------------------------------
if(NegAngMomBra(1) .or. NegAngMomBra(2) .or. NegAngMomBra(3)) then
a1a2a3 = 0d0
!------------------------------------------------------------------------
! Fundamental integral: (000|000)^m
!------------------------------------------------------------------------
elseif(TotAngMomBra(1) == 0 .and. TotAngMomBra(2) == 0 .and. TotAngMomBra(3) == 0) then
a1a2a3 = Om(m)
!------------------------------------------------------------------------
! 1st vertical recurrence relation (4 terms): (a1+00|000)^m
!------------------------------------------------------------------------
elseif(TotAngMomBra(2) == 0 .and. TotAngMomBra(3) == 0) then
do i=1,3
do j=1,3
a1m(i,j) = AngMomBra(i,j)
a1mm(i,j) = AngMomBra(i,j)
end do
end do
! Loop over cartesian directions
xyz = 0
if (AngMomBra(1,1) > 0) then
xyz = 1
elseif(AngMomBra(1,2) > 0) then
xyz = 2
elseif(AngMomBra(1,3) > 0) then
xyz = 3
else
write(*,*) 'xyz = 0 in VRR3e!'
end if
! End loop over cartesian directions
a1m(1,xyz) = a1m(1,xyz) - 1
a1mm(1,xyz) = a1mm(1,xyz) - 2
if(AngMomBra(1,xyz) == 0) then
a1a2a3 = 0d0
elseif(AngMomBra(1,xyz) == 1) then
a1a2a3 = (CenterZA(1,xyz) - DY0(1))*VRR3e(m, a1m, maxm,Om,ExpZ,CenterZA,DY0,DY1,D2Y0,D2Y1) &
- (DY1(1) - DY0(1))*VRR3e(m+1,a1m, maxm,Om,ExpZ,CenterZA,DY0,DY1,D2Y0,D2Y1)
else
a1a2a3 = (CenterZA(1,xyz) - DY0(1))*VRR3e(m, a1m, maxm,Om,ExpZ,CenterZA,DY0,DY1,D2Y0,D2Y1) &
- (DY1(1) - DY0(1))*VRR3e(m+1,a1m, maxm,Om,ExpZ,CenterZA,DY0,DY1,D2Y0,D2Y1) &
+ dble(AngMomBra(1,xyz)-1)*(0.5d0/ExpZ(1) - D2Y0(1,1))*VRR3e(m, a1mm,maxm,Om,ExpZ,CenterZA,DY0,DY1,D2Y0,D2Y1) &
- dble(AngMomBra(1,xyz)-1)*(D2Y1(1,1) - D2Y0(1,1))*VRR3e(m+1,a1mm,maxm,Om,ExpZ,CenterZA,DY0,DY1,D2Y0,D2Y1)
end if
!------------------------------------------------------------------------
! 2nd vertical recurrence relation (6 terms): (a1a2+0|000)^m
!------------------------------------------------------------------------
elseif(TotAngMomBra(3) == 0) then
do i=1,3
do j=1,3
a2m(i,j) = AngMomBra(i,j)
a2mm(i,j) = AngMomBra(i,j)
a1m2m(i,j) = AngMomBra(i,j)
end do
end do
! Loop over cartesian directions
xyz = 0
if (AngMomBra(2,1) > 0) then
xyz = 1
elseif(AngMomBra(2,2) > 0) then
xyz = 2
elseif(AngMomBra(2,3) > 0) then
xyz = 3
else
write(*,*) 'xyz = 0 in VRR3e!'
end if
! End loop over cartesian directions
a2m(2,xyz) = a2m(2,xyz) - 1
a2mm(2,xyz) = a2mm(2,xyz) - 2
a1m2m(1,xyz) = a1m2m(1,xyz) - 1
a1m2m(2,xyz) = a1m2m(2,xyz) - 1
if(AngMomBra(2,xyz) == 0) then
a1a2a3 = 0d0
elseif(AngMomBra(2,xyz) == 1) then
a1a2a3 = (CenterZA(2,xyz) - DY0(2))*VRR3e(m, a2m, maxm,Om,ExpZ,CenterZA,DY0,DY1,D2Y0,D2Y1) &
- (DY1(2) - DY0(2))*VRR3e(m+1,a2m, maxm,Om,ExpZ,CenterZA,DY0,DY1,D2Y0,D2Y1)
else
a1a2a3 = (CenterZA(2,xyz) - DY0(2))*VRR3e(m, a2m, maxm,Om,ExpZ,CenterZA,DY0,DY1,D2Y0,D2Y1) &
- (DY1(2) - DY0(2))*VRR3e(m+1,a2m, maxm,Om,ExpZ,CenterZA,DY0,DY1,D2Y0,D2Y1) &
+ dble(AngMomBra(2,xyz)-1)*(0.5d0/ExpZ(2) - D2Y0(2,2))*VRR3e(m, a2mm, maxm,Om,ExpZ,CenterZA,DY0,DY1,D2Y0,D2Y1) &
- dble(AngMomBra(2,xyz)-1)*(D2Y1(2,2) - D2Y0(2,2))*VRR3e(m+1,a2mm, maxm,Om,ExpZ,CenterZA,DY0,DY1,D2Y0,D2Y1)
end if
if(AngMomBra(1,xyz) > 0) &
a1a2a3 = a1a2a3 &
+ dble(AngMomBra(1,xyz))*(-D2Y0(2,1))*VRR3e(m, a1m2m,maxm,Om,ExpZ,CenterZA,DY0,DY1,D2Y0,D2Y1) &
- dble(AngMomBra(1,xyz))*(D2Y1(2,1) - D2Y0(2,1))*VRR3e(m+1,a1m2m,maxm,Om,ExpZ,CenterZA,DY0,DY1,D2Y0,D2Y1)
!------------------------------------------------------------------------
! 3rd vertical recurrence relation (8 terms): (a1a2a3+|000)^m
!------------------------------------------------------------------------
else
do i=1,3
do j=1,3
a3m(i,j) = AngMomBra(i,j)
a3mm(i,j) = AngMomBra(i,j)
a1m3m(i,j) = AngMomBra(i,j)
a2m3m(i,j) = AngMomBra(i,j)
end do
end do
! Loop over cartesian directions
xyz = 0
if (AngMomBra(3,1) > 0) then
xyz = 1
elseif(AngMomBra(3,2) > 0) then
xyz = 2
elseif(AngMomBra(3,3) > 0) then
xyz = 3
else
write(*,*) 'xyz = 0 in VRR3e!'
end if
! End loop over cartesian directions
a3m(3,xyz) = a3m(3,xyz) - 1
a3mm(3,xyz) = a3mm(3,xyz) - 2
a1m3m(1,xyz) = a1m3m(1,xyz) - 1
a1m3m(3,xyz) = a1m3m(3,xyz) - 1
a2m3m(2,xyz) = a2m3m(2,xyz) - 1
a2m3m(3,xyz) = a2m3m(3,xyz) - 1
if(AngMomBra(3,xyz) == 0) then
a1a2a3 = 0d0
elseif(AngMomBra(3,xyz) == 1) then
a1a2a3 = (CenterZA(3,xyz) - DY0(3))*VRR3e(m, a3m, maxm,Om,ExpZ,CenterZA,DY0,DY1,D2Y0,D2Y1) &
- (DY1(3) - DY0(3))*VRR3e(m+1,a3m, maxm,Om,ExpZ,CenterZA,DY0,DY1,D2Y0,D2Y1)
else
a1a2a3 = (CenterZA(3,xyz) - DY0(3))*VRR3e(m, a3m, maxm,Om,ExpZ,CenterZA,DY0,DY1,D2Y0,D2Y1) &
- (DY1(3) - DY0(3))*VRR3e(m+1,a3m, maxm,Om,ExpZ,CenterZA,DY0,DY1,D2Y0,D2Y1) &
+ dble(AngMomBra(3,xyz)-1)*(0.5d0/ExpZ(3) - D2Y0(3,3))*VRR3e(m, a3mm, maxm,Om,ExpZ,CenterZA,DY0,DY1,D2Y0,D2Y1) &
- dble(AngMomBra(3,xyz)-1)*(D2Y1(3,3) - D2Y0(3,3))*VRR3e(m+1,a3mm, maxm,Om,ExpZ,CenterZA,DY0,DY1,D2Y0,D2Y1)
end if
if(dble(AngMomBra(1,xyz)) > 0) &
a1a2a3 = a1a2a3 &
+ dble(AngMomBra(1,xyz))*(-D2Y0(3,1))*VRR3e(m, a1m3m,maxm,Om,ExpZ,CenterZA,DY0,DY1,D2Y0,D2Y1) &
- dble(AngMomBra(1,xyz))*(D2Y1(3,1) - D2Y0(3,1))*VRR3e(m+1,a1m3m,maxm,Om,ExpZ,CenterZA,DY0,DY1,D2Y0,D2Y1)
if(dble(AngMomBra(2,xyz)) > 0) &
a1a2a3 = a1a2a3 &
+ dble(AngMomBra(2,xyz))*(-D2Y0(3,2))*VRR3e(m, a2m3m,maxm,Om,ExpZ,CenterZA,DY0,DY1,D2Y0,D2Y1) &
- dble(AngMomBra(2,xyz))*(D2Y1(3,2) - D2Y0(3,2))*VRR3e(m+1,a2m3m,maxm,Om,ExpZ,CenterZA,DY0,DY1,D2Y0,D2Y1)
end if
end function VRR3e