mirror of https://gitlab.com/QEF/q-e.git
348 lines
11 KiB
Fortran
348 lines
11 KiB
Fortran
!
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! Copyright (C) 2001 PWSCF group
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! This file is distributed under the terms of the
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! GNU General Public License. See the file `License'
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! in the root directory of the present distribution,
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! or http://www.gnu.org/copyleft/gpl.txt .
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!
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!
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!----------------------------------------------------------------------
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subroutine init_us_1
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!----------------------------------------------------------------------
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!
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! This routine performs the following tasks:
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! a) For each non vanderbilt pseudopotential it computes the D and
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! the betar in the same form of the Vanderbilt pseudopotential.
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! b) It computes the indices indv which establish the correspondence
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! nh <-> beta in the atom
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! c) It computes the indices nhtol which establish the correspondence
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! nh <-> angular momentum of the beta function
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! d) It computes the indices nhtolm which establish the correspondence
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! nh <-> combined (l,m) index for the beta function.
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! e) It computes the coefficients c_{LM}^{nm} which relates the
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! spherical harmonics in the Q expansion
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! f) It computes the radial fourier transform of the Q function on
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! all the g vectors
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! g) It computes the q terms which define the S matrix.
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! h) It fills the interpolation table for the beta functions
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!
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#include "machine.h"
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USE kinds, ONLY: DP
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USE parameters, ONLY: lmaxx, nbrx, lqmax
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USE constants, ONLY: fpi
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USE atom, ONLY: r, rab
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USE basis, ONLY: ntyp
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USE cell_base, ONLY: omega, tpiba
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USE gvect, ONLY: g, gg
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USE pseud, ONLY: lloc, lmax
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USE lsda_mod, ONLY : nspin
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USE us, ONLY: nh,tvanp, okvan, nqxq, dq, nqx, tab,nhtol, nhtoj, nhtolm, &
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dvan, qq, qrad, indv, nhm
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USE uspp_param, ONLY: lqx, dion, betar, qfunc, qfcoef, rinner, nbeta, &
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kkbeta, nqf, nqlc, lll, jjj, lmaxkb
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USE uspp, ONLY : ap, aainit
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USE spin_orb, ONLY : lspinorb, rot_ylm, qq_spinorb, fcoef
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implicit none
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!
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! here a few local variables
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!
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integer :: nt, ih, jh, nb, mb, nmb, l, m, ir, iq, is, startq, &
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lastq, ilast, ndm
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! various counters
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real(kind=DP), allocatable :: aux (:), aux1 (:), besr (:), qtot (:,:,:)
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! various work space
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real(kind=DP) :: prefr, pref, q, qi
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! the prefactor of the q functions
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! the prefactor of the beta functions
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! the modulus of g for each shell
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! q-point grid for interpolation
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real(kind=DP), allocatable :: ylmk0 (:)
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! the spherical harmonics
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real(kind=DP) :: vll (0:lmaxx), vqint, sqrt2, j
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! the denominator in KB case
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! interpolated value
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integer :: n1, m0, m1, n, li, mi, vi, vj, ijs, is1, is2, &
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lk, mk, vk, kh, lh, sph_ind
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complex(kind=DP) :: coeff, qgm(1)
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real(kind=dp) :: spinor, ji, jk
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call start_clock ('init_us_1')
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!
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! Initialization of the variables
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!
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ndm = MAXVAL (kkbeta(1:ntyp))
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allocate (aux ( ndm))
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allocate (aux1( ndm))
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allocate (besr( ndm))
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allocate (qtot( ndm , nbrx , nbrx))
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allocate (ylmk0( lqx * lqx))
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dvan = 0.d0
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qq (:,:,:) = 0.d0
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ap (:,:,:) = 0.d0
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if (lqx > 0) qrad(:,:,:,:)= 0.d0
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prefr = fpi / omega
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if (lspinorb) then
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!
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! In the spin-orbit case we need the unitary matrix u which rotates the
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! real spherical harmonics and yields the complex ones.
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!
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sqrt2=1.d0/dsqrt(2.d0)
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rot_ylm=(0.d0,0.d0)
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l=lmaxx
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rot_ylm(l+1,1)=(1.d0,0.d0)
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do n1=2,2*l+1,2
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m=n1/2
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n=l+1-m
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rot_ylm(n,n1)=dcmplx((-1.d0)**m*sqrt2,0.d0)
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rot_ylm(n,n1+1)=dcmplx(0.d0,-(-1.d0)**m*sqrt2)
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n=l+1+m
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rot_ylm(n,n1)=dcmplx(sqrt2,0.d0)
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rot_ylm(n,n1+1)=dcmplx(0.d0, sqrt2)
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enddo
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fcoef=(0.d0,0.d0)
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qq_spinorb=(0.d0,0.d0)
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endif
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!
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! For each pseudopotential we initialize the indices nhtol, nhtolm,
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! nhtoj, indv, and if the pseudopotential is of KB type we initialize the
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! atomic D terms
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!
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do nt = 1, ntyp
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ih = 1
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do nb = 1, nbeta (nt)
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l = lll (nb, nt)
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j = jjj (nb, nt)
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do m = 1, 2 * l + 1
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nhtol (ih, nt) = l
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nhtolm(ih, nt) = l*l+m
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nhtoj (ih, nt) = j
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indv (ih, nt) = nb
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ih = ih + 1
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enddo
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enddo
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!
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! From now on the only difference between KB and US pseudopotentials
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! is in the presence of the q and Q functions.
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!
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! Here we initialize the D of the solid
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!
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if (lspinorb) then
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!
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! first calculate the fcoef coefficients
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!
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do ih = 1, nh (nt)
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li = nhtol(ih, nt)
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ji = nhtoj(ih, nt)
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mi = nhtolm(ih, nt)-li*li
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vi = indv (ih, nt)
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do kh=1,nh(nt)
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lk = nhtol(kh, nt)
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jk = nhtoj(kh, nt)
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mk = nhtolm(kh, nt)-lk*lk
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vk = indv (kh, nt)
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if (li.eq.lk.and.abs(ji-jk).lt.1.d-7) then
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do is1=1,2
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do is2=1,2
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coeff = (0.d0, 0.d0)
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do m=-li-1, li
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m0= sph_ind(li,ji,m,is1) + lmaxx + 1
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m1= sph_ind(lk,jk,m,is2) + lmaxx + 1
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coeff=coeff + rot_ylm(m0,mi)*spinor(li,ji,m,is1)* &
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conjg(rot_ylm(m1,mk))*spinor(lk,jk,m,is2)
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enddo
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fcoef(ih,kh,is1,is2,nt)=coeff
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enddo
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enddo
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endif
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enddo
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enddo
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!
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! and calculate the bare coefficients
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!
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do ih = 1, nh (nt)
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vi = indv (ih, nt)
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do jh = 1, nh (nt)
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vj = indv (jh, nt)
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ijs=0
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do is1=1,2
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do is2=1,2
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ijs=ijs+1
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dvan(ih,jh,ijs,nt)=dion(vi,vj,nt)*fcoef(ih,jh,is1,is2,nt)
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if (vi.ne.vj) fcoef(ih,jh,is1,is2,nt)=(0.d0,0.d0)
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enddo
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enddo
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enddo
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enddo
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else
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do ih = 1, nh (nt)
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do jh = 1, nh (nt)
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if (nhtol (ih, nt) == nhtol (jh, nt) .and. &
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nhtolm(ih, nt) == nhtolm(jh, nt) ) then
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ir = indv (ih, nt)
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is = indv (jh, nt)
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dvan (ih, jh, 1, nt) = dion (ir, is, nt)
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if (nspin.eq.4) dvan(ih, jh, 4, nt) = dion(ir, is, nt)
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endif
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enddo
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enddo
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endif
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enddo
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!
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! compute Clebsch-Gordan coefficients
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!
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if (okvan) call aainit (lmaxkb + 1)
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!
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! here for the US types we compute the Fourier transform of the
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! Q functions.
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!
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call divide (nqxq, startq, lastq)
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do nt = 1, ntyp
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if (tvanp (nt) ) then
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do l = 0, nqlc (nt) - 1
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!
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! first we build for each nb,mb,l the total Q(|r|) function
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! note that l is the true angular momentum, and the arrays
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! have dimensions 1..l+1
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!
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do nb = 1, nbeta (nt)
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do mb = nb, nbeta (nt)
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if ( (l >= abs (lll (nb, nt) - lll (mb, nt) ) ) .and. &
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(l <= lll (nb, nt) + lll (mb, nt) ) .and. &
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(mod (l + lll (nb, nt) + lll (mb, nt), 2) == 0) ) then
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do ir = 1, kkbeta (nt)
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if (r (ir, nt) >= rinner (l + 1, nt) ) then
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qtot (ir, nb, mb) = qfunc (ir, nb, mb, nt)
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else
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ilast = ir
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endif
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enddo
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if (rinner (l + 1, nt) > 0.d0) &
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call setqf(qfcoef (1, l+1, nb, mb, nt), &
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qtot(1,nb,mb), r(1,nt), nqf(nt),l,ilast)
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endif
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enddo
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enddo
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!
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! here we compute the spherical bessel function for each |g|
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!
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do iq = startq, lastq
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q = (iq - 1) * dq * tpiba
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call sph_bes (kkbeta (nt), r (1, nt), q, l, aux)
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!
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! and then we integrate with all the Q functions
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!
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do nb = 1, nbeta (nt)
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!
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! the Q are symmetric with respect to indices
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!
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do mb = nb, nbeta (nt)
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nmb = mb * (mb - 1) / 2 + nb
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if ( (l >= abs (lll (nb, nt) - lll (mb, nt) ) ) .and. &
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(l <= lll (nb, nt) + lll (mb, nt) ) .and. &
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(mod (l + lll(nb, nt) + lll(mb, nt), 2) == 0) ) then
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do ir = 1, kkbeta (nt)
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aux1 (ir) = aux (ir) * qtot (ir, nb, mb)
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enddo
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call simpson (kkbeta(nt), aux1, rab(1, nt), &
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qrad(iq,nmb,l + 1, nt) )
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endif
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enddo
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enddo
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! igl
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enddo
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! l
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enddo
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qrad (:, :, :, nt) = qrad (:, :, :, nt)*prefr
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#ifdef __PARA
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call reduce (nqxq * nbrx * (nbrx + 1) / 2 * lqx, qrad (1, 1, 1, nt) )
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#endif
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endif
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! ntyp
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enddo
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!
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! and finally we compute the qq coefficients by integrating the Q.
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! q are the g=0 components of Q.
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!
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#ifdef __PARA
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if (gg (1) > 1.0d-8) goto 100
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#endif
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call ylmr2 (lqx * lqx, 1, g, gg, ylmk0)
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do nt = 1, ntyp
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if (tvanp (nt) ) then
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if (lspinorb) then
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do ih=1,nh(nt)
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do jh=1,nh(nt)
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call qvan2 (1, ih, jh, nt, gg, qgm, ylmk0)
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do kh=1,nh(nt)
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do lh=1,nh(nt)
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ijs=0
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do is1=1,2
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do is2=1,2
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ijs=ijs+1
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do is=1,2
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qq_spinorb(kh,lh,ijs,nt) = qq_spinorb(kh,lh,ijs,nt) &
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+ omega*DREAL(qgm(1))*fcoef(kh,ih,is1,is,nt) &
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*fcoef(jh,lh,is,is2,nt)
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enddo
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enddo
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enddo
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enddo
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enddo
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enddo
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enddo
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else
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do ih = 1, nh (nt)
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do jh = ih, nh (nt)
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call qvan2 (1, ih, jh, nt, gg, qgm, ylmk0)
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qq (ih, jh, nt) = omega * DREAL (qgm (1) )
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qq (jh, ih, nt) = qq (ih, jh, nt)
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enddo
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enddo
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endif
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endif
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enddo
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#ifdef __PARA
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100 continue
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if (lspinorb) then
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call reduce ( nhm * nhm * ntyp * 8, qq_spinorb )
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else
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call reduce ( nhm * nhm * ntyp, qq )
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endif
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#endif
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!
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! fill the interpolation table tab
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!
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pref = fpi / sqrt (omega)
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call divide (nqx, startq, lastq)
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tab (:,:,:) = 0.d0
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do nt = 1, ntyp
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do nb = 1, nbeta (nt)
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l = lll (nb, nt)
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do iq = startq, lastq
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qi = (iq - 1) * dq
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call sph_bes (kkbeta (nt), r (1, nt), qi, l, besr)
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do ir = 1, kkbeta (nt)
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aux (ir) = betar (ir, nb, nt) * besr (ir) * r (ir, nt)
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enddo
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call simpson (kkbeta (nt), aux, rab (1, nt), vqint)
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tab (iq, nb, nt) = vqint * pref
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enddo
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enddo
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enddo
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#ifdef __PARA
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call reduce (nqx * nbrx * ntyp, tab)
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#endif
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deallocate (ylmk0)
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deallocate (qtot)
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deallocate (besr)
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deallocate (aux1)
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deallocate (aux)
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call stop_clock ('init_us_1')
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return
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end subroutine init_us_1
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