quantum-espresso/PW/init_us_1.f90

423 lines
14 KiB
Fortran

! Copyright (C) 2001-2007 Quantum ESPRESSO group
! This file is distributed under the terms of the
! GNU General Public License. See the file `License'
! in the root directory of the present distribution,
! or http://www.gnu.org/copyleft/gpl.txt .
!
!
!----------------------------------------------------------------------
subroutine init_us_1
!----------------------------------------------------------------------
!
! This routine performs the following tasks:
! a) For each non vanderbilt pseudopotential it computes the D and
! the betar in the same form of the Vanderbilt pseudopotential.
! b) It computes the indices indv which establish the correspondence
! nh <-> beta in the atom
! c) It computes the indices nhtol which establish the correspondence
! nh <-> angular momentum of the beta function
! d) It computes the indices nhtolm which establish the correspondence
! nh <-> combined (l,m) index for the beta function.
! e) It computes the coefficients c_{LM}^{nm} which relates the
! spherical harmonics in the Q expansion
! f) It computes the radial fourier transform of the Q function on
! all the g vectors
! g) It computes the q terms which define the S matrix.
! h) It fills the interpolation table for the beta functions
!
USE kinds, ONLY : DP
USE parameters, ONLY : lmaxx
USE constants, ONLY : fpi, sqrt2
USE atom, ONLY : rgrid
USE ions_base, ONLY : ntyp => nsp
USE cell_base, ONLY : omega, tpiba
USE gvect, ONLY : g, gg
USE lsda_mod, ONLY : nspin
USE us, ONLY : nqxq, dq, nqx, tab, tab_d2y, qrad, spline_ps
USE splinelib
USE uspp, ONLY : nhtol, nhtoj, nhtolm, ijtoh, dvan, qq, indv,&
ap, aainit, qq_so, dvan_so, okvan
USE uspp_param, ONLY : upf, lmaxq, nbetam, nh, nhm, lmaxkb
USE spin_orb, ONLY : lspinorb, rot_ylm, fcoef
USE paw_variables,ONLY : okpaw
USE mp_global, ONLY : intra_pool_comm
USE mp, ONLY : mp_sum
!
implicit none
!
! here a few local variables
!
integer :: nt, ih, jh, nb, mb, ijv, l, m, ir, iq, is, startq, &
lastq, ilast, ndm
! various counters
real(DP), allocatable :: aux (:), aux1 (:), besr (:), qtot (:,:)
! various work space
real(DP) :: prefr, pref, q, qi
! the prefactor of the q functions
! the prefactor of the beta functions
! the modulus of g for each shell
! q-point grid for interpolation
real(DP), allocatable :: ylmk0 (:)
! the spherical harmonics
real(DP) :: vqint, j
! interpolated value
! J=L+S (noninteger!)
integer :: n1, m0, m1, n, li, mi, vi, vj, ijs, is1, is2, &
lk, mk, vk, kh, lh
integer, external :: sph_ind
complex(DP) :: coeff, qgm(1)
real(DP) :: spinor, ji, jk
!
real(DP), allocatable :: xdata(:)
real(DP) :: d1
!
call start_clock ('init_us_1')
!
! Initialization of the variables
!
ndm = MAXVAL ( upf(:)%kkbeta )
allocate (aux ( ndm))
allocate (aux1( ndm))
allocate (besr( ndm))
allocate (qtot( ndm , nbetam*(nbetam+1)/2 ))
allocate (ylmk0( lmaxq * lmaxq))
ap (:,:,:) = 0.d0
if (lmaxq > 0) qrad(:,:,:,:)= 0.d0
!
! the following prevents an out-of-bound error: upf(nt)%nqlc=2*lmax+1
! but in some versions of the PP files lmax is not set to the maximum
! l of the beta functions but includes the l of the local potential
!
do nt=1,ntyp
upf(nt)%nqlc = MIN ( upf(nt)%nqlc, lmaxq )
IF ( upf(nt)%nqlc < 0 ) upf(nt)%nqlc = 0
end do
prefr = fpi / omega
if (lspinorb) then
!
! In the spin-orbit case we need the unitary matrix u which rotates the
! real spherical harmonics and yields the complex ones.
!
rot_ylm=(0.d0,0.d0)
l=lmaxx
rot_ylm(l+1,1)=(1.d0,0.d0)
do n1=2,2*l+1,2
m=n1/2
n=l+1-m
rot_ylm(n,n1)=CMPLX((-1.d0)**m/sqrt2,0.0_dp,kind=DP)
rot_ylm(n,n1+1)=CMPLX(0.d0,-(-1.d0)**m/sqrt2,kind=DP)
n=l+1+m
rot_ylm(n,n1)=CMPLX(1.0_dp/sqrt2,0.d0,kind=DP)
rot_ylm(n,n1+1)=CMPLX(0.d0, 1.0_dp/sqrt2,kind=DP)
enddo
fcoef=(0.d0,0.d0)
dvan_so = (0.d0,0.d0)
qq_so=(0.d0,0.d0)
qq = 0.d0
else
qq = 0.d0
dvan = 0.d0
endif
!
! For each pseudopotential we initialize the indices nhtol, nhtolm,
! nhtoj, indv, and if the pseudopotential is of KB type we initialize the
! atomic D terms
!
do nt = 1, ntyp
ih = 1
do nb = 1, upf(nt)%nbeta
l = upf(nt)%lll (nb)
do m = 1, 2 * l + 1
nhtol (ih, nt) = l
nhtolm(ih, nt) = l*l+m
indv (ih, nt) = nb
ih = ih + 1
enddo
enddo
if ( upf(nt)%has_so ) then
ih = 1
do nb = 1, upf(nt)%nbeta
l = upf(nt)%lll (nb)
j = upf(nt)%jjj (nb)
do m = 1, 2 * l + 1
nhtoj (ih, nt) = j
ih = ih + 1
enddo
enddo
endif
! ijtoh map augmentation channel indexes ih and jh to composite
! "triangular" index ijh
ijtoh(:,:,nt) = -1
ijv = 0
do ih = 1,nh(nt)
do jh = ih,nh(nt)
ijv = ijv+1
ijtoh(ih,jh,nt) = ijv
ijtoh(jh,ih,nt) = ijv
enddo
enddo
!
! From now on the only difference between KB and US pseudopotentials
! is in the presence of the q and Q functions.
!
! Here we initialize the D of the solid
!
if (upf(nt)%has_so) then
!
! first calculate the fcoef coefficients
!
do ih = 1, nh (nt)
li = nhtol(ih, nt)
ji = nhtoj(ih, nt)
mi = nhtolm(ih, nt)-li*li
vi = indv (ih, nt)
do kh=1,nh(nt)
lk = nhtol(kh, nt)
jk = nhtoj(kh, nt)
mk = nhtolm(kh, nt)-lk*lk
vk = indv (kh, nt)
if (li == lk .and. abs(ji-jk) < 1.d-7) then
do is1=1,2
do is2=1,2
coeff = (0.d0, 0.d0)
do m=-li-1, li
m0= sph_ind(li,ji,m,is1) + lmaxx + 1
m1= sph_ind(lk,jk,m,is2) + lmaxx + 1
coeff=coeff + rot_ylm(m0,mi)*spinor(li,ji,m,is1)* &
CONJG(rot_ylm(m1,mk))*spinor(lk,jk,m,is2)
enddo
fcoef(ih,kh,is1,is2,nt)=coeff
enddo
enddo
endif
enddo
enddo
!
! and calculate the bare coefficients
!
do ih = 1, nh (nt)
vi = indv (ih, nt)
do jh = 1, nh (nt)
vj = indv (jh, nt)
ijs=0
do is1=1,2
do is2=1,2
ijs=ijs+1
dvan_so(ih,jh,ijs,nt) = upf(nt)%dion(vi,vj) * &
fcoef(ih,jh,is1,is2,nt)
if (vi.ne.vj) fcoef(ih,jh,is1,is2,nt)=(0.d0,0.d0)
enddo
enddo
enddo
enddo
else
do ih = 1, nh (nt)
do jh = 1, nh (nt)
if (nhtol (ih, nt) == nhtol (jh, nt) .and. &
nhtolm(ih, nt) == nhtolm(jh, nt) ) then
ir = indv (ih, nt)
is = indv (jh, nt)
if (lspinorb) then
dvan_so (ih, jh, 1, nt) = upf(nt)%dion (ir, is)
dvan_so (ih, jh, 4, nt) = upf(nt)%dion (ir, is)
else
dvan (ih, jh, nt) = upf(nt)%dion (ir, is)
endif
endif
enddo
enddo
endif
enddo
!
! compute Clebsch-Gordan coefficients
!
if (okvan .or. okpaw) call aainit (lmaxkb + 1)
!
! here for the US types we compute the Fourier transform of the
! Q functions.
!
call divide (nqxq, startq, lastq)
!
do nt = 1, ntyp
if ( upf(nt)%tvanp ) then
do l = 0, upf(nt)%nqlc -1
!
! first we build for each nb,mb,l the total Q(|r|) function
! note that l is the true (combined) angular momentum
! and that the arrays have dimensions 0..l (no more 1..l+1)
!
do nb = 1, upf(nt)%nbeta
do mb = nb, upf(nt)%nbeta
respect_sum_rule : &
if ( ( l >= abs(upf(nt)%lll(nb) - upf(nt)%lll(mb)) ) .and. &
( l <= upf(nt)%lll(nb) + upf(nt)%lll(mb) ) .and. &
(mod (l+upf(nt)%lll(nb)+upf(nt)%lll(mb), 2) == 0) ) then
ijv = mb * (mb-1) / 2 + nb
paw : & ! in PAW formalism aug. charge is computed elsewhere
if (upf(nt)%q_with_l .or. upf(nt)%tpawp) then
qtot(1:upf(nt)%kkbeta,ijv) =&
upf(nt)%qfuncl(1:upf(nt)%kkbeta,ijv,l)
else
do ir = 1, upf(nt)%kkbeta
if (rgrid(nt)%r(ir) >=upf(nt)%rinner (l+1) ) then
qtot (ir, ijv) = upf(nt)%qfunc(ir,ijv)
else
ilast = ir
endif
enddo
if ( upf(nt)%rinner (l+1) > 0.0_dp) &
call setqf(upf(nt)%qfcoef (1, l+1, nb, mb), &
qtot(1,ijv), rgrid(nt)%r, upf(nt)%nqf, &
l, ilast)
endif paw
endif respect_sum_rule
enddo ! mb
enddo ! nb
!
! here we compute the spherical bessel function for each |g|
!
do iq = startq, lastq
q = (iq - 1) * dq * tpiba
call sph_bes ( upf(nt)%kkbeta, rgrid(nt)%r, q, l, aux)
!
! and then we integrate with all the Q functions
!
do nb = 1, upf(nt)%nbeta
!
! the Q are symmetric with respect to indices
!
do mb = nb, upf(nt)%nbeta
ijv = mb * (mb - 1) / 2 + nb
if ( ( l >= abs(upf(nt)%lll(nb) - upf(nt)%lll(mb)) ) .and. &
( l <= upf(nt)%lll(nb) + upf(nt)%lll(mb) ) .and. &
(mod(l+upf(nt)%lll(nb)+upf(nt)%lll(mb),2)==0) ) then
do ir = 1, upf(nt)%kkbeta
aux1 (ir) = aux (ir) * qtot (ir, ijv)
enddo
call simpson ( upf(nt)%kkbeta, aux1, rgrid(nt)%rab, &
qrad(iq,ijv,l + 1, nt) )
endif
enddo
enddo
! igl
enddo
! l
enddo
qrad (:, :, :, nt) = qrad (:, :, :, nt)*prefr
#ifdef __PARA
call mp_sum ( qrad (:, :, :, nt), intra_pool_comm )
#endif
endif
! ntyp
enddo
!
! and finally we compute the qq coefficients by integrating the Q.
! q are the g=0 components of Q.
!
#ifdef __PARA
if (gg (1) > 1.0d-8) goto 100
#endif
call ylmr2 (lmaxq * lmaxq, 1, g, gg, ylmk0)
do nt = 1, ntyp
if ( upf(nt)%tvanp ) then
if (upf(nt)%has_so) then
do ih=1,nh(nt)
do jh=1,nh(nt)
call qvan2 (1, ih, jh, nt, gg, qgm, ylmk0)
qq (ih, jh, nt) = omega * DBLE (qgm (1) )
do kh=1,nh(nt)
do lh=1,nh(nt)
ijs=0
do is1=1,2
do is2=1,2
ijs=ijs+1
do is=1,2
qq_so(kh,lh,ijs,nt) = qq_so(kh,lh,ijs,nt) &
+ omega* DBLE(qgm(1))*fcoef(kh,ih,is1,is,nt)&
*fcoef(jh,lh,is,is2,nt)
enddo
enddo
enddo
enddo
enddo
enddo
enddo
else
do ih = 1, nh (nt)
do jh = ih, nh (nt)
call qvan2 (1, ih, jh, nt, gg, qgm, ylmk0)
if (lspinorb) then
qq_so (ih, jh, 1, nt) = omega * DBLE (qgm (1) )
qq_so (jh, ih, 1, nt) = qq_so (ih, jh, 1, nt)
qq_so (ih, jh, 4, nt) = qq_so (ih, jh, 1, nt)
qq_so (jh, ih, 4, nt) = qq_so (ih, jh, 4, nt)
endif
qq (ih, jh, nt) = omega * DBLE (qgm (1) )
qq (jh, ih, nt) = qq (ih, jh, nt)
enddo
enddo
endif
endif
enddo
#ifdef __PARA
100 continue
if (lspinorb) then
call mp_sum( qq_so , intra_pool_comm )
call mp_sum( qq , intra_pool_comm )
else
call mp_sum( qq , intra_pool_comm )
endif
#endif
!
! fill the interpolation table tab
!
pref = fpi / sqrt (omega)
call divide (nqx, startq, lastq)
tab (:,:,:) = 0.d0
do nt = 1, ntyp
do nb = 1, upf(nt)%nbeta
l = upf(nt)%lll (nb)
do iq = startq, lastq
qi = (iq - 1) * dq
call sph_bes (upf(nt)%kkbeta, rgrid(nt)%r, qi, l, besr)
do ir = 1, upf(nt)%kkbeta
aux (ir) = upf(nt)%beta (ir, nb) * besr (ir) * rgrid(nt)%r(ir)
enddo
call simpson (upf(nt)%kkbeta, aux, rgrid(nt)%rab, vqint)
tab (iq, nb, nt) = vqint * pref
enddo
enddo
enddo
#ifdef __PARA
call mp_sum( tab, intra_pool_comm )
#endif
! initialize spline interpolation
if (spline_ps) then
allocate( xdata(nqx) )
do iq = 1, nqx
xdata(iq) = (iq - 1) * dq
enddo
do nt = 1, ntyp
do nb = 1, upf(nt)%nbeta
d1 = (tab(2,nb,nt) - tab(1,nb,nt)) / dq
call spline(xdata, tab(:,nb,nt), 0.d0, d1, tab_d2y(:,nb,nt))
enddo
enddo
deallocate(xdata)
endif
deallocate (ylmk0)
deallocate (qtot)
deallocate (besr)
deallocate (aux1)
deallocate (aux)
call stop_clock ('init_us_1')
return
end subroutine init_us_1