fermie.F90 10 KB
Newer Older
1 2 3 4 5 6 7 8 9 10
MODULE m_fermie
  USE m_juDFT
  !-----------------------------------------------------------------------
  !     determines the fermi energy by
  !            gaussian-integration method                          c.l.fu
  !            triangular method (or tetrahedrons)
  !            or fermi-function                                    p.kurz
  !----------------------------------------------------------------------
CONTAINS
  SUBROUTINE fermie(eig_id, mpi,kpts,obsolete,&
11
       input, noco,e_min,cell,results)
12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30

    !---------------------------------------------------f--------------------
    !
    !     a fist (T=0) approximation to the fermi-energy is determined
    !     by:
    !           zelec = sum { spindg * we }
    !                       e=<ef
    !
    !     TREE STRUCTURE: fermie----sort
    !                           ----fergwt
    !                           ----fertri---triang
    !                                     |--dosint
    !                                     |--dosef -- trisrt
    !                                     +--doswt
    !                           ----ferhis---ef_newton
    !
    !-----------------------------------------------------------------------


Daniel Wortmann's avatar
Daniel Wortmann committed
31
    USE m_eig66_io, ONLY : read_eig,write_eig
32
#if defined(CPP_MPI)&&defined(CPP_NEVER)
33 34 35 36 37 38 39
    USE m_mpi_col_eigJ
#endif
    USE m_sort
    USE m_fertri
    USE m_ferhis
    USE m_fergwt
    USE m_types
40
    USE m_xmlOutput
41 42 43 44 45 46 47 48 49 50 51 52 53 54
    IMPLICIT NONE
    TYPE(t_results),INTENT(INOUT)   :: results
    TYPE(t_mpi),INTENT(IN)   :: mpi
    TYPE(t_obsolete),INTENT(IN)   :: obsolete
    TYPE(t_input),INTENT(IN)   :: input
    TYPE(t_noco),INTENT(IN)   :: noco
    TYPE(t_cell),INTENT(IN)   :: cell
    TYPE(t_kpts),INTENT(IN)   :: kpts
    !     ..
    !     .. Scalar Arguments ..
    INTEGER, INTENT (IN) :: eig_id
    REAL,INTENT(IN)      :: e_min
    !     ..
    !     .. Array Arguments ..
Daniel Wortmann's avatar
Daniel Wortmann committed
55
    !REAL,    INTENT (OUT):: w(:,:,:) !(dimension%neigd,kpts%nkpt,dimension%jspd)
56 57
    !     ..
    !     .. Local Scalars ..
Daniel Wortmann's avatar
Daniel Wortmann committed
58
    REAL del  ,spindg,ssc ,ws,zc,weight,efermi,seigv
59
    INTEGER i,idummy,j,jsp,k,l,n,nbands,nstef,nv,nmat,nspins
60
    INTEGER n_help,m_spins,mspin,sslice(2)
61 62 63 64 65
    !     ..
    !     .. Local Arrays ..
    !
    INTEGER, ALLOCATABLE :: idxeig(:),idxjsp(:),idxkpt(:),INDEX(:)
    REAL,    ALLOCATABLE :: e(:),eig(:,:,:),we(:)
Daniel Wortmann's avatar
Daniel Wortmann committed
66
    INTEGER ne(kpts%nkpt,SIZE(results%w_iks,3))
67
    CHARACTER(LEN=20)    :: attributes(5)
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

    !--- J constants
    !--- J constants

#ifdef CPP_MPI
    INCLUDE 'mpif.h'
    INTEGER, PARAMETER :: comm = MPI_COMM_SELF
    INTEGER*4 :: nv_mpi(2),idum1d(0),idum2d(0,0)
#endif

    !     ..
    !     ..
    !***********************************************************************
    !                  ABBREVIATIONS
    !
    !     eig        : array of eigenvalues 
    !     wtkpt      : list of the weights of each k-point (from inp-file)
    !     e          : linear list of the eigenvalues 
    !     we         : list of weights of the eigenvalues in e
    !     zelec      : number of electrons 
    !     spindg     : spindegeneracy (2 in nonmagnetic calculations)
    !     seigv      : weighted sum of the occupied valence eigenvalues
    !     seigsc     : weighted sum of the semi-core eigenvalues
    !     seigscv    : sum of seigv and seigsc
    !     ts         : entropy contribution to the free energy
    !
    !***********************************************************************
    !     .. Data statements ..
    DATA del/1.0e-6/
    !     ..
    n=SIZE(results%w_iks) !size of list of all eigenvalues
    ALLOCATE (idxeig(n),idxjsp(n),idxkpt(n),INDEX(n),e(n),we(n) )
    ALLOCATE (eig(SIZE(results%w_iks,1),SIZE(results%w_iks,2),SIZE(results%w_iks,3)))

    ! initiliaze e
    e = 0


    IF ( mpi%irank == 0 ) WRITE (6,FMT=8000)
8000 FORMAT (/,/,1x,'fermi energy and band-weighting factors:')
    !
    !---> READ IN EIGENVALUES
    !
    spindg = 2.0/REAL(input%jspins)
    n = 0
    results%seigsc = 0.0
    ssc = 0.0
    n_help = 0
    !
    !---> pk non-collinear
    IF (noco%l_noco) THEN
       nspins = 1
    ELSE
       nspins = input%jspins
    ENDIF
    !---> pk non-collinear
    !
125 126
    IF (mpi%irank == 0) CALL openXMLElementNoAttributes('eigenvalues')
    DO jsp = 1,nspins
127 128 129 130 131 132
       DO  k = 1,kpts%nkpt
          CALL read_eig(eig_id,k,jsp,neig=ne(k,jsp),eig=eig(:,k,jsp))
          IF ( mpi%irank == 0 ) THEN
             WRITE (6,'(a2,3f10.5,f12.6)') 'at',kpts%bk(:,k),kpts%wtkpt(k)
             WRITE (6,'(i5,a14)') ne(k,jsp),' eigenvalues :' 
             WRITE (6,'(8f12.6)') (eig(i,k,jsp),i=1,ne(k,jsp))
133
             attributes = ''
134 135 136 137 138 139
             WRITE(attributes(1),'(i0)') jsp
             WRITE(attributes(2),'(i0)') k
             WRITE(attributes(3),'(f15.8)') kpts%bk(1,k)
             WRITE(attributes(4),'(f15.8)') kpts%bk(2,k)
             WRITE(attributes(5),'(f15.8)') kpts%bk(3,k)
             CALL writeXMLElementPoly('eigenvaluesAt',(/'spin','ikpt','k_x ','k_y ','k_z '/),attributes,eig(1:ne(k,jsp),k,jsp))
140
          END IF
141 142 143 144 145
       END DO
    ENDDO
    !finished reading of eigenvalues
    IF (mpi%irank == 0) CALL closeXMLElement('eigenvalues')

Daniel Wortmann's avatar
Daniel Wortmann committed
146
    IF (ABS(input%fixed_moment)<1E-6) THEN
147 148 149 150 151
       !this is a standard calculation
       m_spins=1
    else
       !total moment is fixed
       m_spins=2
Daniel Wortmann's avatar
Daniel Wortmann committed
152
    END IF
153

Daniel Wortmann's avatar
Daniel Wortmann committed
154
    results%seigv = 0.0e0
155 156 157 158 159 160 161 162 163 164 165
    do mspin=1,m_spins
       IF (m_spins    == 1) THEN
          sslice = (/1,nspins/)
       ELSE
          sslice = (/mspin,mspin/)
          nspins = 1
       ENDIF
       n = 0
       DO jsp = sslice(1),sslice(2)
          !Generate a list of energies
          DO  k = 1,kpts%nkpt
Daniel Wortmann's avatar
Daniel Wortmann committed
166 167 168 169 170 171 172 173 174 175 176 177 178
             !
             !--->          STORE EIGENVALUES AND WEIGHTS IN A LINEAR LIST. AND MEMORIZE 
             !--->          CONECTION TO THE ORIGINAL ARRAYS
             !
             DO  j = 1,ne(k,jsp)
                e(n+j) = eig(j,k,jsp)
                we(n+j) = kpts%wtkpt(k)
                idxeig(n+j) = j+n_help
                idxkpt(n+j) = k
                idxjsp(n+j) = jsp
             END DO
             !--->          COUNT THE NUMBER OF EIGENVALUES
             n = n + ne(k,jsp)
179
          END DO
180 181
       END DO

182
       CALL sort(index,e)
183

Daniel Wortmann's avatar
Daniel Wortmann committed
184 185 186 187 188 189 190 191 192
       !     Check if no deep eigenvalue is found
       IF (e_min-MINVAL(e(1:n))>1.0) THEN
          WRITE(6,*) 'WARNING: Too low eigenvalue detected:'
          WRITE(6,*) 'min E=', MINVAL(e(1:n)),' min(enpara)=',&
               &             e_min
          CALL juDFT_warn("Too low eigenvalue detected",calledby="fermi" &
               &     ,hint ="If the lowest eigenvalue is more than 1Htr below "//&
               &     "the lowest energy parameter, you probably have picked up"//&
               &     " a ghoststate")
193
       END IF
Daniel Wortmann's avatar
Daniel Wortmann committed
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
       !
       !---> DETERMINE EF BY SUMMING WEIGHTS
       !
       weight = input%zelec/spindg
       seigv=0.0
       IF(m_spins /= 1) weight = weight/2.0  -(mspin-1.5)*input%fixed_moment
       ws = 0.0e0
       l = 0
       DO WHILE ((ws+del).LT.weight)
          l = l + 1
          IF (l.GT.n) THEN
             IF ( mpi%irank == 0 ) THEN
                WRITE (6,FMT=8010) n,ws,weight
             END IF
             CALL juDFT_error("Not enough eavefunctions",calledby="fermie")
8010         FORMAT (/,10x,'error: not enough wavefunctions.',i10,2d20.10)
          END IF
          ws = ws + we(INDEX(l))
          seigv =seigv + e(INDEX(l))*we(INDEX(l))*spindg
          !         WRITE (6,FMT='(2f10.7)') e(index(l)),we(index(l))
       END DO
       results%ef = e(INDEX(l))
       nstef = l
       zc = input%zelec
       IF(m_spins /= 1) THEN
          zc = zc/2.0-(mspin-1.5)*input%fixed_moment
          idxjsp = 1 !assume single spin in following calculations
          IF (mspin == 1) THEN
             WRITE(6,*) "Fixed total moment calculation"
             WRITE(6,*) "Moment:",input%fixed_moment
             write(6,*) "First Spin:"
          ELSE
             WRITE(6,*) "Second Spin:"
          ENDIF
228
       ENDIF
229

Daniel Wortmann's avatar
Daniel Wortmann committed
230
       IF ( mpi%irank == 0 ) WRITE (6,FMT=8020) results%ef,nstef,seigv,ws,results%seigsc,ssc
231

Daniel Wortmann's avatar
Daniel Wortmann committed
232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255
       !+po
       results%ts = 0.0
       !-po
       results%w_iks(:,:,sslice(1):sslice(2)) = 0.0
       results%bandgap = 0.0
       IF (input%gauss) THEN
          CALL fergwt(kpts,input,mpi,ne(:,sslice(1):sslice(2)), eig(:,:,sslice(1):sslice(2)),results%ef,results%w_iks(:,:,sslice(1):sslice(2)),results%seigv)
       ELSE IF (input%tria) THEN
          CALL fertri(input,kpts,mpi%irank, ne(:,sslice(1):sslice(2)),kpts%nkpt,nspins,zc,eig(:,:,sslice(1):sslice(2)),kpts%bk,spindg,&
               results%ef,results%seigv,results%w_iks(:,:,sslice(1):sslice(2)))
       ELSE
          CALL ferhis(input,kpts,mpi,index,idxeig,idxkpt,idxjsp, n,&
               nstef,ws,spindg,weight,e,ne(:,sslice(1):sslice(2)),we, noco,cell,results%ef,results%seigv,results%w_iks(:,:,sslice(1):sslice(2)),results)
       END IF
       results%seigscv = results%seigsc + results%seigv

       IF (mspin == 2) THEN
          WRITE(6,*) "Different Fermi-energies for both spins:"
          WRITE(6,"(a,f0.3,a,f0.4,a,f0.4,a,f0.4)") "Fixed Moment:" &
               ,input%fixed_moment,"   Difference(EF):",efermi," - ",results%ef,"="&
               ,efermi-results%ef
       ENDIF
       efermi = results%ef
    enddo
256
    DEALLOCATE ( idxeig,idxjsp,idxkpt,index,e,eig,we )
257 258

    attributes = ''
259
    WRITE(attributes(1),'(f20.10)') results%ef
260
    WRITE(attributes(2),'(a)') 'Htr'
261 262
    IF (mpi%irank.EQ.0) CALL writeXMLElement('FermiEnergy',(/'value','units'/),attributes(1:2))

Daniel Wortmann's avatar
Daniel Wortmann committed
263 264 265 266 267 268
    !Put w_iks into eig-file
    DO jsp = 1,nspins
       DO  k = 1,kpts%nkpt
          CALL write_eig(eig_id,k,jsp,w_iks=results%w_iks(:,k,jsp))
       ENDDO
    ENDDO
Daniel Wortmann's avatar
Daniel Wortmann committed
269

270 271
    RETURN
8020 FORMAT (/,'FERMIE:',/,&
Daniel Wortmann's avatar
Daniel Wortmann committed
272
         &       10x,'first approx. to ef    (T=0)  :',f10.6,' htr',&
273 274
         &       '   (energy of the highest occ. eigenvalue)',/,&
         &       10x,'number of occ. states  (T=0)  :',i10,/,&
Daniel Wortmann's avatar
Daniel Wortmann committed
275
         &       10x,'first approx. to seigv (T=0)  :',f10.6,' htr',/,&
276 277 278 279
         &       10x,'sum of weights of occ. states :',f10.6,/,&
         &       10x,'sum of semicore eigenvalues   :',f10.6,' htr',/,&
         &       10x,'sum of semicore charge        :',f10.6,' e',/)
  END SUBROUTINE fermie
Daniel Wortmann's avatar
Daniel Wortmann committed
280
END MODULE m_fermie