! ! Copyright (C) 2001 PWSCF 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 . ! #include "f_defs.h" ! !----------------------------------------------------------------------- subroutine new_ns !----------------------------------------------------------------------- ! ! This routine computes the new value for ns (the occupation numbers of ! ortogonalized atomic wfcs). ! These quantities are defined as follows: ns_{I,s,m1,m2} = \sum_{k,v} ! f_{kv} <\fi^{at}_{I,m1}|\psi_{k,v,s}><\psi_{k,v,s}|\fi^{at}_{I,m2}> ! USE io_global, ONLY : stdout USE kinds, ONLY : DP USE atom, ONLY : lchi, nchi, oc USE ions_base, ONLY : nat, ityp USE basis, ONLY : natomwfc USE klist, ONLY : nks USE ldaU, ONLY : ns, nsnew, Hubbard_lmax, Hubbard_l, & Hubbard_U, Hubbard_alpha, swfcatom, & eth, d1, d2, d3 USE lsda_mod, ONLY : lsda, current_spin, nspin, isk USE symme, ONLY : nsym, irt USE wvfct, ONLY : nbnd, npw, npwx, igk, wg, gamma_only USE wavefunctions_module, ONLY : evc USE gvect, ONLY : gstart use io_files #ifdef __PARA use para #endif implicit none ! integer :: ik, ibnd, is, i, na, nb, nt, isym, n, counter, m1, m2, & m0, m00, l, ldim integer, allocatable :: offset (:) ! counter on k points ! " " bands ! " " spins ! offset of d electrons of atom d ! in the natomwfc ordering real(kind=DP) , allocatable :: nr (:,:,:,:) real(kind=DP) :: t0, scnds ! cpu time spent real(kind=DP), external :: DDOT complex(kind=DP) :: ZDOTC complex(kind=DP) , allocatable :: proj(:,:) real(kind=DP) :: psum t0 = scnds () ldim = 2 * Hubbard_lmax + 1 allocate( offset(nat), proj(natomwfc,nbnd), nr(ldim,ldim,nspin,nat) ) ! ! D_Sl for l=1, l=2 and l=3 are already initialized, for l=0 D_S0 is 1 ! counter = 0 do na = 1, nat nt = ityp (na) do n = 1, nchi (nt) if (oc (n, nt) >= 0.d0) then l = lchi (n, nt) if (l == Hubbard_l(nt)) offset (na) = counter counter = counter + 2 * l + 1 endif enddo enddo if (counter.ne.natomwfc) call errore ('new_ns', 'nstart<>counter', 1) nr (:,:,:,:) = 0.d0 nsnew (:,:,:,:) = 0.d0 ! ! we start a loop on k points ! if (nks.gt.1) rewind (iunigk) do ik = 1, nks if (lsda) current_spin = isk(ik) if (nks.gt.1) read (iunigk) npw, igk if (nks.gt.1) call davcio (evc, nwordwfc, iunwfc, ik, - 1) call davcio (swfcatom, nwordatwfc, iunat, ik, - 1) ! ! make the projection ! do ibnd = 1, nbnd do i = 1, natomwfc if ( gamma_only ) then proj (i, ibnd) = 2.d0 * & DDOT(2*npw, swfcatom (1, i), 1, evc (1, ibnd), 1) if (gstart.eq.2) proj (i, ibnd) = proj (i, ibnd) - & swfcatom (1, i) * evc (1, ibnd) else proj (i, ibnd) = ZDOTC (npw, swfcatom (1, i), 1, evc (1, ibnd), 1) endif enddo enddo #ifdef __PARA call reduce (2 * natomwfc * nbnd, proj) #endif ! ! compute the occupation numbers (the quantities n(m1,m2)) of the ! atomic orbitals ! do na = 1, nat nt = ityp (na) if (Hubbard_U(nt).ne.0.d0 .or. Hubbard_alpha(nt).ne.0.d0) then do m1 = 1, 2 * Hubbard_l(nt) + 1 do m2 = m1, 2 * Hubbard_l(nt) + 1 do ibnd = 1, nbnd nr(m1,m2,current_spin,na) = nr(m1,m2,current_spin,na) + & wg(ibnd,ik) * DREAL( proj(offset(na)+m2,ibnd) * & conjg(proj(offset(na)+m1,ibnd)) ) enddo enddo enddo endif enddo ! on k-points enddo #ifdef __PARA call poolreduce (ldim * ldim * nspin * nat , nr) #endif if (nspin.eq.1) nr = 0.5d0 * nr ! ! impose hermiticity of n_{m1,m2} ! do na = 1, nat nt = ityp(na) do is = 1, nspin do m1 = 1, 2 * Hubbard_l(nt) + 1 do m2 = m1 + 1, 2 * Hubbard_l(nt) + 1 nr (m2, m1, is, na) = nr (m1, m2, is, na) enddo enddo enddo enddo ! symmetryze the quantities nr -> nsnew do na = 1, nat nt = ityp (na) if (Hubbard_U(nt).ne.0.d0 .or. Hubbard_alpha(nt).ne.0.d0) then do is = 1, nspin do m1 = 1, 2 * Hubbard_l(nt) + 1 do m2 = 1, 2 * Hubbard_l(nt) + 1 do isym = 1, nsym nb = irt (isym, na) do m0 = 1, 2 * Hubbard_l(nt) + 1 do m00 = 1, 2 * Hubbard_l(nt) + 1 if (Hubbard_l(nt).eq.0) then nsnew(m1,m2,is,na) = nsnew(m1,m2,is,na) + & nr(m0,m00,is,nb) / nsym else if (Hubbard_l(nt).eq.1) then nsnew(m1,m2,is,na) = nsnew(m1,m2,is,na) + & d1(m0 ,m1,isym) * nr(m0,m00,is,nb) * & d1(m00,m2,isym) / nsym else if (Hubbard_l(nt).eq.2) then nsnew(m1,m2,is,na) = nsnew(m1,m2,is,na) + & d2(m0 ,m1,isym) * nr(m0,m00,is,nb) * & d2(m00,m2,isym) / nsym else if (Hubbard_l(nt).eq.3) then nsnew(m1,m2,is,na) = nsnew(m1,m2,is,na) + & d3(m0 ,m1,isym) * nr(m0,m00,is,nb) * & d3(m00,m2,isym) / nsym else call errore ('new_ns', & 'angular momentum not implemented', & abs(Hubbard_l(nt)) ) end if enddo enddo enddo enddo enddo enddo endif enddo ! Now we make the matrix ns(m1,m2) strictly hermitean do na = 1, nat nt = ityp (na) if (Hubbard_U(nt).ne.0.d0 .or. Hubbard_alpha(nt).ne.0.d0) then do is = 1, nspin do m1 = 1, 2 * Hubbard_l(nt) + 1 do m2 = m1, 2 * Hubbard_l(nt) + 1 psum = abs ( nsnew(m1,m2,is,na) - nsnew(m1,m2,is,na) ) if (psum.gt.1.d-10) then WRITE( stdout, * ) na, is, m1, m2 WRITE( stdout, * ) nsnew (m1, m2, is, na) WRITE( stdout, * ) nsnew (m2, m1, is, na) call errore ('new_ns', 'non hermitean matrix', 1) else nsnew(m1,m2,is,na) = 0.5d0 * (nsnew(m1,m2,is,na) + & nsnew(m2,m1,is,na) ) nsnew(m2,m1,is,na) = nsnew(m1,m2,is,na) endif enddo enddo enddo endif enddo ! ! Now the contribution to the total energy is computed. The corrections ! needed to obtain a variational expression are already included ! eth = 0.d0 do na = 1, nat nt = ityp (na) if (Hubbard_U(nt).ne.0.d0 .or. Hubbard_alpha(nt).ne.0.d0) then do is = 1, nspin do m1 = 1, 2 * Hubbard_l(nt) + 1 do m2 = 1, 2 * Hubbard_l(nt) + 1 eth = eth + Hubbard_U(nt) * nsnew(m1,m2,is,na) * & (ns(m2,m1,is,na) - nsnew(m2,m1,is,na) * 0.5d0) enddo enddo enddo endif enddo deallocate ( offset, proj, nr ) if (nspin.eq.1) eth = 2.d0 * eth return end subroutine new_ns