[Wien] problem with Xcrysden 3D fermi surface for Ca

C. Strandkvist cs530 at cam.ac.uk
Mon Aug 24 17:05:00 CEST 2009


Dear WIEN2k users,

I using Xcrysden to generate 3D fermisurfaces and in general it does give 
results consistent with what I find in the literature (e.g. the TiC example 
featured on the Xcrysden website). At the moment I am looking at calcium 
and using the command 'xcrysden --wien_fermisurface directory' command line 
option to generate the 3D fermi surface using my WIEN2k files. The problem 
is that my fermi surface does not agree with what I find in literature, and 
in particular it is clearly wrong as the fermi surfaces on the hexagonal 
faces of the Brillouin zone are not identical (which they should be from 
symmetry as Ca is an FCC cubic structure). When generating the fermi 
surface for Ca under pressure it also becomes clear that the volumes of the 
electron and hole surfaces are not equivalent. I have tried using a larger 
number of k-points (up to 15000) thinking that there could be an issue with 
the resolution, which did not make a difference. I have also checked that 
my WIEN2k files do generate the correct results for bandstructure and DoS 
calculations. I have copied in my .struct file and my .scf file below. Any 
suggestions as to what the problem might be will be greatly appreciated.

Thank you

Charlotte Strandkvist

----------------- Cafermi F LATTICE,NONEQUIV.ATOMS: 1225_Fm-3m MODE OF 
CALC=RELA unit=bohr
 10.506000 10.506000 10.506000 90.000000 90.000000 90.000000 ATOM 1: 
X=0.00000000 Y=0.00000000 Z=0.00000000
          MULT= 1 ISPLIT= 2 Ca NPT= 781 R0=0.00005000 RMT= 2.5000 Z: 20.0 
LOCAL ROT MATRIX: 1.0000000 0.0000000 0.0000000
                     0.0000000 1.0000000 0.0000000
                     0.0000000 0.0000000 1.0000000
--------------------------

:ITE005:  5. ITERATION
            ---------

:NATO :    1 INDEPENDEND AND    1 TOTAL ATOMS IN UNITCELL
       SUBSTANCE: Cafermi

       LATTICE                      = F   
: POT : POTENTIAL OPTION 13 LAT : LATTICE CONSTANTS= 10.50600 10.50600 
: 10.50600 1.571 1.571 1.571 VOL : UNIT CELL VOLUME = 289.90266
       MODE OF CALCULATION IS       = RELA
       NON-SPINPOLARIZED CALCULATION
:IFFT  : FFT-parameters:   90   90   90 Factor: 2.00
       ATOMNUMBER=  1 Ca         VCOUL-ZERO = -0.20848E-01
:FIT001: SIGMA OF V-XC FIT FOR ATOM  1  0.3347513E-04
:FIT001: SIGMA OF V-XC FIT FOR ATOM  1  0.3347513E-04
:DEN  : DENSITY INTEGRALS =            -562.828100   (Ry)
       ELS_POTENTIAL_AT Z=0 and Z=0.5:  -1.04823  -1.04823
       ELS_POTENTIAL_AT Y=0 and Y=0.5:   0.00000   0.00000
: VZERO:v0,v0c,v0x -1.72062 -1.04823 -0.67239 v5,v5c,v5x -1.72062 -1.04823 
: -0.67239 VZERY:v0,v0c,v0x -0.52455 0.00000 -0.52455 v5,v5c,v5x -0.52455 
: 0.00000 -0.52455 VZERX:v0,v0c,v0x -0.52455 0.00000 -0.52455 v5,v5c,v5x 
: -0.52455 0.00000 -0.52455

          ATOMIC SPHERE DEPENDENT PARAMETERS FOR ATOM  Ca        
:e__0001: OVERALL ENERGY PARAMETER IS    0.3000
          OVERALL BASIS SET ON ATOM IS LAPW
:E0_0001: E( 0)=    0.3000
             APW+lo
:E0_0001: E( 0)=   -2.9295   E(BOTTOM)=   -3.055   E(TOP)=   -2.804
             LOCAL ORBITAL
:E1_0001: E( 1)=   -1.5460   E(BOTTOM)=   -1.778   E(TOP)=   -1.314
             APW+lo
:E1_0001: E( 1)=    0.3000
             LOCAL ORBITAL

       K=   0.00000   0.00000   0.00000            1
:RKM  : MATRIX SIZE  121LOs:   8  RKM= 6.69  WEIGHT= 1.00  PGR:    
       EIGENVALUES ARE:
: EIG00001: -2.9041572 -1.5008486 -1.5008486 -1.5008486 -0.1035986 
: EIG00006: 0.3639558 0.3639558 0.3639558 0.4409919 0.4409919 EIG00011: 
: 0.8535843 0.9955382 0.9955382 0.9955382 1.1554812 EIG00016: 1.2799016 
: 1.2799016 1.2799016 1.3852570 1.3852570 EIG00021: 1.3852570 1.6280016 
: 1.6280016 1.9114766
       ********************************************************

:KPT   :      NUMBER OF K-POINTS:   165
:GMA  : POTENTIAL AND CHARGE CUT-OFF  12.00 Ry**.5
         Bandranges (emin - emax) and occupancy:
:BAN00001:   1   -2.904157   -2.902925  2.00000000
:BAN00002:   2   -1.510270   -1.500849  2.00000000
:BAN00003:   3   -1.506994   -1.500849  2.00000000
:BAN00004:   4   -1.504385   -1.500849  2.00000000
:BAN00005:   5   -0.103599    0.203303  1.92021337
:BAN00006:   6    0.178730    0.363956  0.07978813
:BAN00007:   7    0.242837    0.384090  0.00000000
:BAN00008:   8    0.357123    0.489458  0.00000000
:BAN00009:   9    0.394995    0.505777  0.00000000
:BAN00010:  10    0.436339    0.555662  0.00000000
:BAN00011:  11    0.535797    0.904499  0.00000000
        Energy to separate low and high energystates:   -0.15360


:NOE  : NUMBER OF ELECTRONS          =  10.000

:FER  : F E R M I - ENERGY(TETRAH.M.)=   0.19090




:POS001: AT.NR.   1 POSITION = 0.00000 0.00000 0.00000  MULTIPLICITY =  1

       LMMAX  5
       LM=   0 0  4 0  4 4  6 0  6 4

: CHA001: TOTAL CHARGE INSIDE SPHERE 1 = 8.183339 PCS001: PARTIAL CHARGES 
: SPHERE = 1 S,P,D,F, D-EG,D-T2G QTL001: 2.1236 5.8960 0.1634 0.0003 0.0000 
: 0.0000 0.0000 0.0898 0.0735 0.0000 0.0000 0.0000
        Q-s-low E-s-low Q-p-low E-p-low Q-d-low E-d-low Q-f-low E-f-low
: EPL001: 1.9813 -2.9032 5.8222 -1.5048 0.0000 10.0000 0.0000 10.0000
        Q-s-hi E-s-hi Q-p-hi E-p-hi Q-d-hi E-d-hi Q-f-hi E-f-hi
: EPH001: 0.1423 0.0592 0.0738 0.1109 0.1633 0.1446 0.0003 0.1470

:CHA  : TOTAL CHARGE INSIDE UNIT CELL =      10.000001

:SUM  : SUM OF EIGENVALUES =         -14.649455754


        1.ATOM      Ca                    4 CORE STATES
:1S 001: 1S                -289.680115723 Ry
:2S 001: 2S                 -29.883302557 Ry
:2PP001: 2P*                -24.212124779 Ry
:2P 001: 2P                 -23.941082052 Ry

       DENSITY AT NUCLEUS
        JATOM    VALENCE       SEMI-CORE            CORE           TOTAL

:RTO001:   1       63.414237        0.000000     6139.895785     6203.310022
     
       CHARGES OF NEW CHARGE DENSITY
:NTO  : TOTAL   INTERSTITIAL CHARGE=    1.8166621
:NTO001: TOTAL   CHARGE IN SPHERE  1 =       18.1833393

:NEC01: NUCLEAR AND ELECTRONIC CHARGE     20.00000    20.00000     1.00000
     
       CHARGES OF OLD CHARGE DENSITY
:OTO  : TOTAL   INTERSTITIAL CHARGE=    1.8166043
:OTO001: TOTAL   CHARGE IN SPHERE  1 =       18.1833957

:NEC02: NUCLEAR AND ELECTRONIC CHARGE     20.00000    20.00000     1.00000
     
       CONVERGENCE TEST
:DTO001: TOTAL   DIFFERENCE CHARGE**2 IN SPHERE  1 =  0.0012993

: DIS : CHARGE DISTANCE ( 0.0012993 for atom 1 spin 1) 0.0012993 BIG check 
: (qbig,qrms,qtot) 0.433D-03 0.919D-03 0.130D-02
 
******************************************************
* MULTISECANT MIXING OPTIONS                         *
* NFL Limit   0.100000                               *
* Diag Parm   0.000500                               *
* Standard Increase/Decrease Bounds                  *
* Plane Wave SQRT Dynamic Rescaling                  *
* Max Number of Memory Steps    8                    *
******************************************************
 
:PLANE:  INTERSTITIAL TOTAL      1.89663 DISTAN   0.0000468
:CHARG:  CLM CHARGE   TOTAL      1.48420 DISTAN   0.0002571
:REDuction and DMIX in Broyd:    1.0974    0.2000
:INFO :  Dynamic rescale   0.207D+01
:INFO :  Number of Memory Steps    4 Skipping    0
:INFO :  Reduction   0.0894 Expected   0.1245 Next   0.9994 All   0.1148
:INFO :  Bounds         0.111D+00  0.200D+00  0.100D+00  0.100D+00
:DIRM :  MEMORY 4/8 RESCALE  2.074 RED    0.089 PRED  0.125 NEXT  0.999
:INFO :  DMIXM and Projections     0.100D+00  0.999D+00
:DIRP :  |BROYD|= 0.173D-03 |PRATT|= 0.165D-03 ANGLE=   3.2 DEGREES
:DIRB :  |BROYD|= 0.164D-02 |PRATT|= 0.162D-02 ANGLE=   4.4 DEGREES
       MSEC1 MIXING SCHEME WITH 0.100
     
       CHARGES OF MIXED CHARGE DENSITY
:CTO  : TOTAL   INTERSTITIAL CHARGE=    1.8166180
:CTO001: TOTAL   CHARGE IN SPHERE  1 =       18.1833820

:NEC03: NUCLEAR AND ELECTRONIC CHARGE     20.00000    20.00000     1.00000


:ENE  : ********** TOTAL ENERGY IN Ry =        -1360.792970

------------------------


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