wann_nabla_rs.f 13.4 KB
Newer Older
1 2 3 4 5 6
!--------------------------------------------------------------------------------
! Copyright (c) 2016 Peter Grünberg Institut, Forschungszentrum Jülich, Germany
! This file is part of FLEUR and available as free software under the conditions
! of the MIT license as expressed in the LICENSE file in more detail.
!--------------------------------------------------------------------------------

7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393
      module m_wann_nabla_rs
      use m_juDFT
      contains 
      subroutine wann_nabla_rs(
     >          rvecnum,rvec,kpoints,
     >          jspins_in,nkpts,l_bzsym,film,l_onedimens,
     >          l_soc,band_min,band_max,neigd,
     >          l_socmmn0,wan90version)
c*************************************************
c     Calculate the matrix elements of nabla
c     in real space from the
c     files WF1.chk (and WF1_um.dat) produced
c     by wannier90.
c     FF, December 2009
c*************************************************
      use m_constants, only:pimach
      use m_wann_read_umatrix

      implicit none
      integer, intent(in) :: rvecnum
      integer, intent(in) :: rvec(:,:)
      real,    intent(in) :: kpoints(:,:)
      integer, intent(in) :: jspins_in
      integer, intent(in) :: nkpts
      logical, intent(in) :: l_bzsym
      logical, intent(in) :: film
      logical, intent(in) :: l_onedimens

      logical, intent(in) :: l_soc
      integer, intent(in) :: band_min(2),band_max(2),neigd

      logical, intent(in) :: l_socmmn0
      integer, intent(in) :: wan90version

      integer             :: ikpt,jspins
      integer             :: kpts
      logical             :: l_file
c      real                :: kpoints(3,nkpts)
      integer             :: num_wann,num_kpts,num_nnmax,jspin
      integer             :: kspin,kkspin
      integer             :: wann_shift,num_wann2
      integer             :: i,j,k,m,info,r1,r2,r3,dummy1
      integer             :: dummy2,dummy3,dummy4
      integer             :: hopmin,hopmax,counter,m1,m2
      integer             :: num_bands2
      integer,allocatable :: iwork(:)
      real,allocatable    :: energy(:,:),ei(:)
      real,allocatable    :: eigw(:,:),rwork(:)
      complex,allocatable :: work(:),vec(:,:)
      complex,allocatable :: u_matrix(:,:,:),hwann(:,:,:,:)
      complex,allocatable :: hreal(:,:,:,:)
      complex,allocatable :: hrealsoc(:,:,:,:,:,:,:)
      complex,allocatable :: hwannsoc(:,:,:,:,:)
      complex,allocatable :: nablamat(:,:,:,:,:)
      complex,allocatable :: nablamat2(:,:,:,:)
      complex             :: fac,eulav,eulav1
      real                :: tmp_omi,rdotk,tpi,minenerg,maxenerg
      real, allocatable   :: minieni(:),maxieni(:)
      character           :: jobz,uplo
      integer             :: kpt,band,lee,lwork,lrwork,liwork,n,lda
      complex             :: value(4)
      logical             :: um_format,l_she
      logical             :: repro_eig
      logical             :: l_chk,l_proj
      logical             :: have_disentangled
      integer,allocatable :: ndimwin(:)
      logical,allocatable :: lwindow(:,:)
      integer             :: chk_unit,nkp,ntmp,ierr
      character(len=33)   :: header
      character(len=20)   :: checkpoint
      real                :: tmp_latt(3,3), tmp_kpt_latt(3,nkpts)
      real                :: omega_invariant
      complex,allocatable :: u_matrix_opt(:,:,:)
      integer             :: num_bands
      logical             :: l_umdat
      real,allocatable    :: eigval2(:,:)
      real,allocatable    :: eigval_opt(:,:)
      real                :: scale,a,b
      character(len=2)    :: spinspin12(0:2)
      character(len=3)    :: spin12(2)
      character(len=6)    :: filename
      integer             :: jp,mp,kk
      integer             :: rvecind

      data spinspin12/'  ','.1' , '.2'/
      data spin12/'WF1','WF2'/

      inquire(file='she',exist=l_she)

      tpi=2*pimach()

      jspins=jspins_in
      if(l_soc)jspins=1

      write(6,*)"nkpts=",nkpts

c$$$c***************************************************
c$$$c     read in the kpoints from w90kpts or kpts
c$$$c***************************************************      
c$$$      if (l_bzsym) then
c$$$         l_file=.false.
c$$$         inquire(file='w90kpts',exist=l_file)
c$$$         if (.not.l_file) stop 'where is w90kpts?'
c$$$         open(177,file='w90kpts',form='formatted')
c$$$         read(177,*)kpts,scale
c$$$      else
c$$$         l_file=.false.
c$$$         inquire(file='kpts',exist=l_file)
c$$$         if(.not.l_file) stop 'where is kpts?'
c$$$         open(177,file='kpts',form='formatted')
c$$$         read(177,*)kpts,scale
c$$$      endif   
c$$$      if(kpts.ne.nkpts) stop 'mismatch in number of kpoints'
c$$$
c$$$      do ikpt = 1,nkpts 
c$$$         read(177,*)kpoints(:,ikpt)
c$$$      enddo 
c$$$
c$$$      if(film.and..not.l_onedimens)then
c$$$         kpoints(3,:)=0.0
c$$$      endif   
c$$$      kpoints=kpoints/scale
c$$$      close(177)

      do jspin=1,jspins  !spin loop
c*****************************************************
c     get num_bands and num_wann from the proj file
c*****************************************************
         do j=jspin,0,-1
          inquire(file=trim('proj'//spinspin12(j)),exist=l_file)
          if(l_file)then
            filename='proj'//spinspin12(j)
            exit
          endif
         enddo
         if(l_file)then
          open (203,file=trim(filename),status='old')
          rewind (203)
         else
            CALL juDFT_error("no proj/proj.1/proj.2",calledby
     +           ="wann_nabla_rs")
         endif
         read (203,*) num_wann,num_bands
         close (203)
         write(6,*)'According to proj there are ',num_bands,' bands'
         write(6,*)"and ",num_wann," wannier functions."

c****************************************************************
c        read in chk
c****************************************************************
         num_kpts=nkpts
         allocate( u_matrix_opt(num_bands,num_wann,nkpts) )
         allocate( u_matrix(num_wann,num_wann,nkpts) )
         allocate( lwindow(num_bands,nkpts) )
         allocate( ndimwin(nkpts) )
         call wann_read_umatrix2(
     >            nkpts,num_wann,num_bands,
     >            um_format,jspin,wan90version,
     <            have_disentangled,
     <            lwindow,ndimwin,
     <            u_matrix_opt,u_matrix)

         num_bands2=num_bands
         if(l_soc.and.l_socmmn0)then
          num_bands2=neigd
         endif
 
c************************************************
c        Read the files "WF1.nabl" and "WF2.nabl"
c************************************************
         allocate( nablamat(3,num_bands2,num_bands2,nkpts,2) )
         open(304,file=spin12(jspin)//'.nabl',form='formatted')
         read(304,*)
         read(304,*)
         do nkp=1,num_kpts
          do i=1,num_bands2
           do j=1,num_bands2
            do k=1,3  
             read(304,*)dummy1,dummy2,dummy3,dummy4,a,b
             nablamat(k,j,i,nkp,1)=cmplx(a,-b)
            enddo !k 
           enddo !j
          enddo !i
         enddo !nkp
         close(304)

         if(l_soc)then
          open(304,file=spin12(2)//'.nabl',form='formatted')
          read(304,*)
          read(304,*)
          do nkp=1,num_kpts
           do i=1,num_bands2
            do j=1,num_bands2
             do k=1,3  
              read(304,*)dummy1,dummy2,dummy3,dummy4,a,b
              nablamat(k,j,i,nkp,2)=cmplx(a,-b)
             enddo !k 
            enddo !j
           enddo !i
          enddo !nkp
          close(304)
         endif

c**************************************
c        Enforce Hermiticity
c**************************************
         do nkp=1,num_kpts
          do i=1,num_bands2
           do j=1,i
            do k=1,3
             nablamat(k,i,j,nkp,1)=( nablamat(k,i,j,nkp,1)+
     &                         conjg(nablamat(k,j,i,nkp,1)) )/2.0
             nablamat(k,j,i,nkp,1)=conjg(nablamat(k,i,j,nkp,1))
             if(l_soc)then
               nablamat(k,i,j,nkp,2)=( nablamat(k,i,j,nkp,2)+
     &                         conjg(nablamat(k,j,i,nkp,2)) )/2.0
               nablamat(k,j,i,nkp,2)=conjg(nablamat(k,i,j,nkp,2))
             endif
            enddo !k
           enddo !j
          enddo !i
         enddo !nkp

c**************************************
c        Nabla-sum
c**************************************
         if( l_soc )then
          if(l_she)then
           do nkp=1,num_kpts
            do i=1,num_bands2
             do j=1,num_bands2
              do k=1,3  
               nablamat(k,j,i,nkp,1)=nablamat(k,j,i,nkp,1)
     &                            -nablamat(k,j,i,nkp,2)
              enddo !k 
             enddo !j
            enddo !i
           enddo !nkp
          else   
           do nkp=1,num_kpts
            do i=1,num_bands2
             do j=1,num_bands2
              do k=1,3  
               nablamat(k,j,i,nkp,1)=nablamat(k,j,i,nkp,1)
     &                            +nablamat(k,j,i,nkp,2)
              enddo !k 
             enddo !j
            enddo !i
           enddo !nkp
          endif
         endif !jspins.eq.2

c****************************************************************
c        Calculate matrix elements of Nabla in the basis of
c        rotated Bloch functions.
c****************************************************************
         allocate( nablamat2(3,num_wann,num_wann,nkpts) )
         write(6,*)"calculate matrix elements of momentum operator
     &   between wannier orbitals"

         if(have_disentangled) then       
          nablamat2=0.0  
          do nkp=1,num_kpts
           do j=1,num_wann
            do jp=1,num_wann  
             do m=1,ndimwin(nkp)
              do mp=1,ndimwin(nkp)  
               do k=1,3  
                nablamat2(k,jp,j,nkp)=nablamat2(k,jp,j,nkp)+ 
     &                 conjg(u_matrix_opt(mp,jp,nkp))*
     &                        nablamat(k,mp,m,nkp,1)*
     &                       u_matrix_opt(m,j,nkp)
               enddo !k 
              enddo !mp  
             enddo !m
            enddo !jp 
           enddo !j
          enddo !nkp
         else
          nablamat2(:,:,:,:)=nablamat(:,:,:,:,1)
         end if                    !have_disentangled

         allocate(hwann(3,num_wann,num_wann,num_kpts))
         hwann=cmplx(0.0,0.0)
         wann_shift=0
         if(l_socmmn0)then
            wann_shift=band_min(jspin)-1
         endif
         do k=1,num_kpts
          do m=1,num_wann
           do i=1,num_wann
            do j=1,num_wann
             do mp=1,num_wann
              do kk=1,3  
                hwann(kk,mp,m,k)=hwann(kk,mp,m,k)+
     *              conjg(u_matrix(j,mp,k))*
     *                nablamat2(kk,j,i,k)*
     *                    u_matrix(i,m,k)
              enddo !kk
             enddo !mp   
            enddo !j
           enddo !i
          enddo !m
         enddo !k

c************************************************************
c        Calculate matrix elements in real space.
c***********************************************************      
         write(6,*)"calculate nabla-mat in rs"
c$$$         hopmin=-5
c$$$         hopmax=5
c$$$         allocate(hreal(3,num_wann,num_wann,hopmin:hopmax,
c$$$     &         hopmin:hopmax,hopmin:hopmax))
c$$$         hreal=cmplx(0.0,0.0)
c$$$         do r3=hopmin,hopmax
c$$$          do r2=hopmin,hopmax
c$$$           do r1=hopmin,hopmax
c$$$            do k=1,nkpts  
c$$$              rdotk=tpi*(kpoints(1,k)*r1+kpoints(2,k)*r2+
c$$$     &                                   kpoints(3,k)*r3)
c$$$              fac=cmplx(cos(rdotk),-sin(rdotk))/nkpts
c$$$              do i=1,num_wann
c$$$               do j=1,num_wann
c$$$                do kk=1,3
c$$$                 hreal(kk,j,i,r1,r2,r3)=
c$$$     &                   hreal(kk,j,i,r1,r2,r3)+
c$$$     &                   fac*hwann(kk,j,i,k)
c$$$                enddo !kk
c$$$               enddo !j
c$$$              enddo !i
c$$$            enddo !k
c$$$           enddo !r1
c$$$          enddo !r2
c$$$         enddo !r3


         allocate(hreal(3,num_wann,num_wann,rvecnum))
         hreal=cmplx(0.0,0.0)

         do rvecind=1,rvecnum
            do k=1,nkpts  
              rdotk=tpi*(kpoints(1,k)*rvec(1,rvecind)+
     &                   kpoints(2,k)*rvec(2,rvecind)+
     &                   kpoints(3,k)*rvec(3,rvecind) )
              fac=cmplx(cos(rdotk),-sin(rdotk))
              do i=1,num_wann
               do j=1,num_wann
                do kk=1,3
                 hreal(kk,j,i,rvecind)=
     &                   hreal(kk,j,i,rvecind)+
     &                   fac*hwann(kk,j,i,k)
                enddo !kk
               enddo !j
              enddo !i
            enddo !k
         enddo !rvecind
         hreal=hreal/cmplx(real(nkpts),0.0)

         if(l_she)then
          open(321,file='rs_sv'//spinspin12(jspin),form='formatted')
         else   
          open(321,file='rsnabla'//spinspin12(jspin),form='formatted')
         endif

         do rvecind=1,rvecnum
            r3=rvec(3,rvecind)
            r2=rvec(2,rvecind)
            r1=rvec(1,rvecind)             
            do j=1,num_wann
             do i=1,num_wann
              do kk=1,3  
               write(321,'(i3,1x,i3,1x,i3,1x,i3,
     &                 1x,i3,1x,i3,1x,f20.8,1x,f20.8)')
     &                 r1,r2,r3,i,j,kk,hreal(kk,i,j,rvecind) 
              enddo !kk  
             enddo !j
            enddo !i
         enddo !rvecind  
         close(321)

         deallocate(lwindow,u_matrix_opt,ndimwin)
         deallocate(u_matrix,hwann,hreal)
         deallocate(nablamat,nablamat2)
      enddo !jspin

      end subroutine wann_nabla_rs
      end module m_wann_nabla_rs