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mirror of https://github.com/TREX-CoE/irpjast.git synced 2024-12-24 21:34:04 +01:00
irpjast/electrons.irp.f

207 lines
4.6 KiB
Fortran

integer function size_8(n)
implicit none
integer, intent(in) :: n
integer :: n8
n8 = ((n-1)/8+1) * 8
if (popcnt(n8) == 1) then
! Power of two, shift by 8
n8 = n8 + 8
endif
size_8 = n8
end
BEGIN_PROVIDER [ integer, nelec_8 ]
implicit none
integer, external :: size_8
nelec_8 = size_8(nelec)
END_PROVIDER
BEGIN_PROVIDER [ integer, nelec ]
implicit none
BEGIN_DOC
! Number of electrons
END_DOC
character*(32) :: buffer
integer, external :: iargc
if (iargc() == 0) then
nelec = 10
else
call getarg(1,buffer)
read(buffer,*)nelec
endif
END_PROVIDER
BEGIN_PROVIDER [ integer, nelec_up ]
implicit none
BEGIN_DOC
! Number of alpha and beta electrons
END_DOC
nelec_up = nelec/2
END_PROVIDER
BEGIN_PROVIDER [ double precision, elec_coord, (nelec, 3) ]
implicit none
BEGIN_DOC
! Electron coordinates
END_DOC
character(len=*), parameter :: FILE_NAME = "elec_coord.txt"
integer :: fu, rc, i, j
open(action='read', file=FILE_NAME, iostat=rc, newunit=fu)
do i = 1, nelec
read(fu, *) elec_coord(i, :)
end do
close(fu)
END_PROVIDER
BEGIN_PROVIDER [ double precision, elec_dist, (nelec, nelec) ]
implicit none
BEGIN_DOC
! e-e distance
END_DOC
integer :: i, j
double precision :: x, y, z
do j = 1, nelec
do i = 1, nelec
x = elec_coord(i, 1) - elec_coord(j, 1)
y = elec_coord(i, 2) - elec_coord(j, 2)
z = elec_coord(i, 3) - elec_coord(j, 3)
elec_dist(i, j) = dsqrt( x*x + y*y + z*z )
enddo
! elec_dist(j, j) = 1.d-10
enddo
END_PROVIDER
BEGIN_PROVIDER [double precision, asymp_jasb, (2)]
BEGIN_DOC
! Asymptotic component subtracted from J_ee
END_DOC
implicit none
integer :: i, p
double precision :: asym_one, x
asym_one = bord_vect(1) * kappa_inv / (1.0d0 + bord_vect(2) * kappa_inv)
asymp_jasb(:) = (/asym_one, 0.5d0 * asym_one/)
do i = 1, 2
x = kappa_inv
do p = 2, nbord
x = x * kappa_inv
asymp_jasb(i) = asymp_jasb(i) + bord_vect(p + 1) * x
end do
end do
END_PROVIDER
BEGIN_PROVIDER [double precision, factor_ee]
implicit none
BEGIN_DOC
! Electron-electron contribution to Jastrow factor
END_DOC
integer :: i, j, p, ipar
double precision :: pow_ser, x, spin_fact
factor_ee = 0.0d0
do j = 1, nelec
do i = 1, j - 1
x = rescale_ee(i, j)
pow_ser = 0.0d0
spin_fact = 1.0d0
ipar = 1
do p = 2, nbord
x = x * rescale_ee(i, j)
pow_ser = pow_ser + bord_vect(p + 1) * x
end do
if (j.le.nelec_up .or. i.gt.nelec_up) then
spin_fact = 0.5d0
ipar = 2
end if
factor_ee = factor_ee + spin_fact * bord_vect(1) * rescale_ee(i, j) &
/ (1.0d0 + bord_vect(2) * rescale_ee(i, j)) - asymp_jasb(ipar) + pow_ser
end do
end do
END_PROVIDER
BEGIN_PROVIDER [double precision, factor_ee_deriv_e, (4, nelec) ]
implicit none
BEGIN_DOC
! Dimensions 1-3 : dx, dy, dz
! Dimension 4 : d2x + d2y + d2z
END_DOC
integer :: i, ii, j, p
double precision :: x, x_inv, y, den, invden, lap1, lap2, lap3, third, spin_fact
double precision, dimension(3) :: pow_ser_g
double precision, dimension(4) :: dx
factor_ee_deriv_e = 0.0d0
third = 1.0d0 / 3.0d0
do j = 1 , nelec
do i = 1, nelec
pow_ser_g = 0.0d0
spin_fact = 1.0d0
den = 1.0d0 + bord_vect(2) * rescale_ee(i, j)
invden = 1.0d0 / den
x_inv = 1.0d0 / (rescale_ee(i, j) + 1.0d-18)
do ii = 1, 4
dx(ii) = rescale_ee_deriv_e(ii, j, i)
enddo
if ((i.le.nelec_up .and. j.le.nelec_up) .or. &
(i.gt.nelec_up .and. j.gt.nelec_up)) then
spin_fact = 0.5d0
end if
lap1 = 0.0d0
lap2 = 0.0d0
lap3 = 0.0d0
do ii = 1, 3
x = rescale_ee(i, j)
do p = 2, nbord
! p a_{p+1} r[i,j]^(p-1)
y = p * bord_vect(p + 1) * x
pow_ser_g(ii) += y * dx(ii)
! (p-1) p a_{p+1} r[i,j]^(p-2) r'[i,j]^2
lap1 += (p - 1) * y * x_inv * dx(ii) * dx(ii)
! p a_{p+1} r[i,j]^(p-1) r''[i,j]
lap2 += y
x = x * rescale_ee(i, j)
end do
! (a1 (-2 a2 r'[i,j]^2+(1+a2 r[i,j]) r''[i,j]))/(1+a2 r[i,j])^3
lap3 += -2.0d0 * bord_vect(2) * dx(ii) * dx(ii)
! \frac{a1 * r'(i,j)}{(a2 * r(i,j)+1)^2}
factor_ee_deriv_e(ii, j) += spin_fact * bord_vect(1) &
* dx(ii) * invden * invden + pow_ser_g(ii)
enddo
ii = 4
lap2 *= dx(ii) * third
lap3 += den * dx(ii)
lap3 *= spin_fact * bord_vect(1) * invden * invden * invden
factor_ee_deriv_e(ii, j) += lap1 + lap2 + lap3
end do
end do
END_PROVIDER