[Wien] How to resolve the large charge fluctuation problem inheterojunction calculation

Peter Blaha pblaha at theochem.tuwien.ac.at
Fri Apr 7 08:36:27 CEST 2006


I'm a bit surprised. This should be a semiconductor, thus charge fluctuations
should be small. Is :NEC01  ok ?
Did you reduce the mixing parameter  in case.inm  ?


"Valid" parameters which a user might have to change during init or later are:

mixing in case.inm  (reduce to eg. 0.1 or down to 0.01)
changing RKmax  in case.in1
changing the Fermi method in case.in2 (smearing may help convergence in metals)
changing the k-mesh (x kgen)
Changing E-parameters (only after some scf cycles have been done or QTL-B
        messages appear)

Regards

> Dear Blaha,
> 
>       I have recalculated it and use the default parameters. But I still meet the ghost band problem.
> Maybe it come from the large charge transfer? Then how to resolve it?
> 
> 
>           ATOMIC SPHERE DEPENDENT PARAMETERS FOR ATOM  N 1       
>           OVERALL ENERGY PARAMETER IS    0.3000
>           OVERALL BASIS SET ON ATOM IS LAPW
>           E( 0)=   -1.1400   E(BOTTOM)=   -2.560   E(TOP)= -200.000
>              APW+lo
>           E( 0)=    0.3000
>              LOCAL ORBITAL
>           E( 1)=    0.3000
>              APW+lo
> 
>           ATOMIC SPHERE DEPENDENT PARAMETERS FOR ATOM  N 2       
>           OVERALL ENERGY PARAMETER IS    0.3000
>           OVERALL BASIS SET ON ATOM IS LAPW
>           E( 0)=   -1.8000   E(BOTTOM)=   -4.410   E(TOP)=    0.810
>              APW+lo
>           E( 0)=    0.3000
>              LOCAL ORBITAL
>           E( 1)=    0.3000
>              APW+lo
> 
>           ATOMIC SPHERE DEPENDENT PARAMETERS FOR ATOM  N 3       
>           OVERALL ENERGY PARAMETER IS    0.3000
>           OVERALL BASIS SET ON ATOM IS LAPW
>           E( 0)=   -2.8600   E(BOTTOM)=   -5.470   E(TOP)=   -0.250
>              APW+lo
>           E( 0)=    0.3000
>              LOCAL ORBITAL
>           E( 1)=    0.3000
>              APW+lo
> 
>           ATOMIC SPHERE DEPENDENT PARAMETERS FOR ATOM  N 4       
>           OVERALL ENERGY PARAMETER IS    0.3000
>           OVERALL BASIS SET ON ATOM IS LAPW
>           E( 0)=   -2.9500   E(BOTTOM)=   -5.560   E(TOP)=   -0.340
>              APW+lo
>           E( 0)=    0.3000
>              LOCAL ORBITAL
>           E( 1)=    0.3000
>              APW+lo
> 
>           ATOMIC SPHERE DEPENDENT PARAMETERS FOR ATOM  N 5       
>           OVERALL ENERGY PARAMETER IS    0.3000
>           OVERALL BASIS SET ON ATOM IS LAPW
>           E( 0)=   -2.4400   E(BOTTOM)=   -5.050   E(TOP)=    0.170
>              APW+lo
>           E( 0)=    0.3000
>              LOCAL ORBITAL
>           E( 1)=    0.3000
>              APW+lo
> 
>           ATOMIC SPHERE DEPENDENT PARAMETERS FOR ATOM  N 6       
>           OVERALL ENERGY PARAMETER IS    0.3000
>           OVERALL BASIS SET ON ATOM IS LAPW
>           E( 0)=   -1.3900   E(BOTTOM)=   -4.000   E(TOP)=    1.220
>              APW+lo
>           E( 0)=    0.3000
>              LOCAL ORBITAL
>           E( 1)=    0.3000
>              APW+lo
> 
>           ATOMIC SPHERE DEPENDENT PARAMETERS FOR ATOM  N 7       
>           OVERALL ENERGY PARAMETER IS    0.3000
>           OVERALL BASIS SET ON ATOM IS LAPW
>           E( 0)=   -1.1400   E(BOTTOM)=   -2.250   E(TOP)= -200.000
>              APW+lo
>           E( 0)=    0.3000
>              LOCAL ORBITAL
>           E( 1)=    0.3000
>              APW+lo
> 
>           ATOMIC SPHERE DEPENDENT PARAMETERS FOR ATOM  N 8       
>           OVERALL ENERGY PARAMETER IS    0.3000
>           OVERALL BASIS SET ON ATOM IS LAPW
>           E( 0)=   -0.3900   E(BOTTOM)=   -0.390   E(TOP)= -200.000
>              APW+lo
>           E( 0)=    0.3000
>              LOCAL ORBITAL
>           E( 1)=    0.3000
>              APW+lo
> 
>           ATOMIC SPHERE DEPENDENT PARAMETERS FOR ATOM  N 9       
>           OVERALL ENERGY PARAMETER IS    0.3000
>           OVERALL BASIS SET ON ATOM IS LAPW
>           E( 0)=    0.6700   E(BOTTOM)=    0.670   E(TOP)= -200.000
>              APW+lo
>           E( 0)=    0.3000
>              LOCAL ORBITAL
>           E( 1)=    0.3000
>              APW+lo
> 
>           ATOMIC SPHERE DEPENDENT PARAMETERS FOR ATOM  N 10      
>           OVERALL ENERGY PARAMETER IS    0.3000
>           OVERALL BASIS SET ON ATOM IS LAPW
>           E( 0)=    0.7600   E(BOTTOM)=    0.760   E(TOP)= -200.000
>              APW+lo
>           E( 0)=    0.3000
>              LOCAL ORBITAL
>           E( 1)=    0.3000
>              APW+lo
> 
>           ATOMIC SPHERE DEPENDENT PARAMETERS FOR ATOM  N 11      
>           OVERALL ENERGY PARAMETER IS    0.3000
>           OVERALL BASIS SET ON ATOM IS LAPW
>           E( 0)=    0.2500   E(BOTTOM)=    0.250   E(TOP)= -200.000
>              APW+lo
>           E( 0)=    0.3000
>              LOCAL ORBITAL
>           E( 1)=    0.3000
>              APW+lo
> 
>           ATOMIC SPHERE DEPENDENT PARAMETERS FOR ATOM  N 12      
>           OVERALL ENERGY PARAMETER IS    0.3000
>           OVERALL BASIS SET ON ATOM IS LAPW
>           E( 0)=   -0.8000   E(BOTTOM)=   -0.800   E(TOP)= -200.000
>              APW+lo
>           E( 0)=    0.3000
>              LOCAL ORBITAL
>           E( 1)=    0.3000
>              APW+lo
> 
>           ATOMIC SPHERE DEPENDENT PARAMETERS FOR ATOM  Al1       
>           OVERALL ENERGY PARAMETER IS    0.3000
>           OVERALL BASIS SET ON ATOM IS LAPW
>           E( 1)=    0.3000
>              APW+lo
>           E( 1)=   -5.2300   E(BOTTOM)=   -5.250   E(TOP)=   -5.210
>              LOCAL ORBITAL
>           E( 0)=    0.3000
>              APW+lo
> 
>           ATOMIC SPHERE DEPENDENT PARAMETERS FOR ATOM  Al2       
>           OVERALL ENERGY PARAMETER IS    0.3000
>           OVERALL BASIS SET ON ATOM IS LAPW
>           E( 1)=    0.3000
>              APW+lo
>           E( 1)=   -6.7400   E(BOTTOM)=   -6.760   E(TOP)=   -6.720
>              LOCAL ORBITAL
>           E( 0)=    0.3000
>              APW+lo
> 
>           ATOMIC SPHERE DEPENDENT PARAMETERS FOR ATOM  Al3       
>           OVERALL ENERGY PARAMETER IS    0.3000
>           OVERALL BASIS SET ON ATOM IS LAPW
>           E( 1)=    0.3000
>              APW+lo
>           E( 1)=   -1.1775   E(BOTTOM)=   -2.890   E(TOP)=    0.535
>              LOCAL ORBITAL
>           E( 0)=    0.3000
>              APW+lo
> 
>           ATOMIC SPHERE DEPENDENT PARAMETERS FOR ATOM  Al4       
>           OVERALL ENERGY PARAMETER IS    0.3000
>           OVERALL BASIS SET ON ATOM IS LAPW
>           E( 1)=    0.3000
>              APW+lo
>           E( 1)=   -7.0050   E(BOTTOM)=   -7.025   E(TOP)=   -6.985
>              LOCAL ORBITAL
>           E( 0)=    0.3000
>              APW+lo
> 
>           ATOMIC SPHERE DEPENDENT PARAMETERS FOR ATOM  Al5       
>           OVERALL ENERGY PARAMETER IS    0.3000
>           OVERALL BASIS SET ON ATOM IS LAPW
>           E( 1)=    0.3000
>              APW+lo
>           E( 1)=   -6.2625   E(BOTTOM)=   -6.285   E(TOP)=   -6.240
>              LOCAL ORBITAL
>           E( 0)=    0.3000
>              APW+lo
> 
>           ATOMIC SPHERE DEPENDENT PARAMETERS FOR ATOM  Al6       
>           OVERALL ENERGY PARAMETER IS    0.3000
>           OVERALL BASIS SET ON ATOM IS LAPW
>           E( 1)=    0.3000
>              APW+lo
>           E( 1)=   -4.8725   E(BOTTOM)=   -4.895   E(TOP)=   -4.850
>              LOCAL ORBITAL
>           E( 0)=    0.3000
>              APW+lo
> 
>           ATOMIC SPHERE DEPENDENT PARAMETERS FOR ATOM  Ga1       
>           OVERALL ENERGY PARAMETER IS    0.3000
>           OVERALL BASIS SET ON ATOM IS LAPW
>           E( 2)=    0.6750   E(BOTTOM)=    0.540   E(TOP)=    0.810
>              APW+lo
>           E( 2)=    0.3000
>              LOCAL ORBITAL
>           E( 0)=    0.3000
>              APW+lo
>           E( 1)=    0.3000
>              APW+lo
> 
>           ATOMIC SPHERE DEPENDENT PARAMETERS FOR ATOM  Ga2       
>           OVERALL ENERGY PARAMETER IS    0.3000
>           OVERALL BASIS SET ON ATOM IS LAPW
>           E( 2)=    2.0500   E(BOTTOM)=    2.050   E(TOP)= -200.000
>              APW+lo
>           E( 2)=    0.3000
>              LOCAL ORBITAL
>           E( 0)=    0.3000
>              APW+lo
>           E( 1)=    0.3000
>              APW+lo
> 
>           ATOMIC SPHERE DEPENDENT PARAMETERS FOR ATOM  Ga3       
>           OVERALL ENERGY PARAMETER IS    0.3000
>           OVERALL BASIS SET ON ATOM IS LAPW
>           E( 2)=    2.5700   E(BOTTOM)=    2.570   E(TOP)= -200.000
>              APW+lo
>           E( 2)=    0.3000
>              LOCAL ORBITAL
>           E( 0)=    0.3000
>              APW+lo
>           E( 1)=    0.3000
>              APW+lo
> 
>           ATOMIC SPHERE DEPENDENT PARAMETERS FOR ATOM  Ga4       
>           OVERALL ENERGY PARAMETER IS    0.3000
>           OVERALL BASIS SET ON ATOM IS LAPW
>           E( 2)=    2.3100   E(BOTTOM)=    2.310   E(TOP)= -200.000
>              APW+lo
>           E( 2)=    0.3000
>              LOCAL ORBITAL
>           E( 0)=    0.3000
>              APW+lo
>           E( 1)=    0.3000
>              APW+lo
> 
>           ATOMIC SPHERE DEPENDENT PARAMETERS FOR ATOM  Ga5       
>           OVERALL ENERGY PARAMETER IS    0.3000
>           OVERALL BASIS SET ON ATOM IS LAPW
>           E( 2)=    1.5700   E(BOTTOM)=    1.570   E(TOP)= -200.000
>              APW+lo
>           E( 2)=    0.3000
>              LOCAL ORBITAL
>           E( 0)=    0.3000
>              APW+lo
>           E( 1)=    0.3000
>              APW+lo
> 
>           ATOMIC SPHERE DEPENDENT PARAMETERS FOR ATOM  Ga6       
>           OVERALL ENERGY PARAMETER IS    0.3000
>           OVERALL BASIS SET ON ATOM IS LAPW
>           E( 2)=    0.3150   E(BOTTOM)=    0.180   E(TOP)=    0.450
>              APW+lo
>           E( 2)=    0.3000
>              LOCAL ORBITAL
>           E( 0)=    0.3000
>              APW+lo
>           E( 1)=    0.3000
>              APW+lo
> 
>        K=   0.06250   0.06250   0.50000            1
> :RKM  : MATRIX SIZE 3936LOs: 186  RKM= 7.00  WEIGHT= 4.00  PGR:    
>        EIGENVALUES ARE:
>         -7.0063557   -7.0051532   -6.9827785   -6.7417578   -6.7391812
>         -6.7183020   -6.2647178   -6.2646134   -6.2382995   -5.2306459
>         -5.2298290   -5.2114638   -4.8768996   -4.8765654   -4.8491701
>         -3.8243257   -3.7376670   -3.3440456   -3.0025592   -2.9212361
>         -2.8932474   -2.8749723   -2.8000437   -2.7824048   -2.7657827
>         -2.5697635   -2.4255291   -2.4008978   -2.3668646   -2.3065403
>         -2.2903693   -1.9603944   -1.9467808   -1.9174030   -1.9061796
>         -1.8287644   -1.8127265   -1.8100594   -1.7773985   -1.7335476
> 
>         -1.6103158   -1.5711023   -1.5547347   -1.5355543   -1.4724515
>         -1.4463006   -1.4287535   -1.3949647   -1.3832499   -1.3571350
>         -1.2892688   -1.1930385   -1.1532157   -1.1264544   -1.1162131
>         -1.0951781   -1.0724066   -0.9991268   -0.9648641   -0.9368415
>         -0.9176971   -0.8916600   -0.8846459   -0.7981152   -0.7839267
>         -0.7574581   -0.7439856   -0.6732781   -0.6628117   -0.6244081
>         -0.5543078   -0.5296252   -0.5145254   -0.5113407   -0.4493951
>         -0.4236344   -0.4045207   -0.3612177   -0.3270388   -0.3127941
> 
>         -0.3093504   -0.2406499   -0.2221350   -0.2002873   -0.1691162
>         -0.1623940   -0.1208905   -0.0942055   -0.0835416   -0.0392296
>         -0.0306514    0.0017381    0.0387782    0.0598622    0.0860118
>          0.1012150    0.1375686    0.1496281    0.2081158    0.2130173
>          0.2352987    0.2413130    0.2549271    0.2704812    0.2911220
>          0.3160394    0.3350662    0.3363291    0.3447647    0.3502275
>          0.3751639    0.3994547    0.4098435    0.4452137    0.4461333
>          0.4736183    0.4947378    0.5111861    0.5287433    0.5514942
> 
>          0.5904748    0.6094103    0.6209726    0.6502127    0.6740732
>          0.6854527    0.6939267    0.7058567    0.7114752    0.7291866
>          0.7495734    0.7586211    0.7818314    0.8059766    0.8139476
>          0.8419154    0.8895921    0.9083172    0.9393209    0.9681194
>          0.9953645    1.0040781    1.0148926    1.0554180    1.0773843
>          1.1152208    1.1298656    1.1398754    1.1504908    1.1654595
>          1.2057136    1.2229277    1.2589478    1.2873022    1.3090981
>          1.3252146    1.3505564    1.3877707    1.3968751    1.4200236
> 
>          1.4312847    1.4583182    1.4750201    1.4828854
>        ********************************************************
> 
>        NUMBER OF K-POINTS:            16
> 
> 
> >No wonder that you get convergence problems when you set EMIN in case.in1c
> >to -3.0 Ry  . Whith this setting you eventually cutoff the Ga-3d states.
> >
> >Start over from scratch and do not change the defaults.
> >
> >> Dear wien users,
> >> 
> >>         I am calculating a heterojunction of AlN/GaN. I find a large 
> >> charge fluctuation in the beginning of iteration and of course the ghost 
> >> band. This is the case.scf1 file, from which you can find the difference 
> >> of energy parameters of N atoms for the two sides of this superlattice 
> >> (1~6 for AlN, 7~12 for GaN) are very large. I have reduce the mxing parameter 
> >> to 0.0001, and still can not resolve this problem. Does any body can give me 
> >> some suggest?
> >> 
> >>           ATOMIC SPHERE DEPENDENT PARAMETERS FOR ATOM  Ga1       
> >>           OVERALL ENERGY PARAMETER IS    0.3000
> >>           OVERALL BASIS SET ON ATOM IS LAPW
> >>           E( 2)=    0.7000   E(BOTTOM)=    0.570   E(TOP)=    0.830
> >>              APW+lo
> >>           E( 2)=    1.0000
> >>              LOCAL ORBITAL
> >>           E( 0)=    0.3000
> >>              APW+lo
> >>           E( 1)=    0.3000
> >>              APW+lo
> >> 
> >>           ATOMIC SPHERE DEPENDENT PARAMETERS FOR ATOM  Ga2       
> >>           OVERALL ENERGY PARAMETER IS    0.3000
> >>           OVERALL BASIS SET ON ATOM IS LAPW
> >>           E( 2)=    2.0800   E(BOTTOM)=    2.080   E(TOP)= -200.000
> >>              APW+lo
> >>           E( 2)=    1.0000
> >>              LOCAL ORBITAL
> >>           E( 0)=    0.3000
> >>              APW+lo
> >>           E( 1)=    0.3000
> >>              APW+lo
> >> 
> >>           ATOMIC SPHERE DEPENDENT PARAMETERS FOR ATOM  Ga3       
> >>           OVERALL ENERGY PARAMETER IS    0.3000
> >>           OVERALL BASIS SET ON ATOM IS LAPW
> >>           E( 2)=    2.6100   E(BOTTOM)=    2.610   E(TOP)= -200.000
> >>              APW+lo
> >>           E( 2)=    1.0000
> >>              LOCAL ORBITAL
> >>           E( 0)=    0.3000
> >>              APW+lo
> >>           E( 1)=    0.3000
> >>              APW+lo
> >> 
> >>           ATOMIC SPHERE DEPENDENT PARAMETERS FOR ATOM  Ga4       
> >>           OVERALL ENERGY PARAMETER IS    0.3000
> >>           OVERALL BASIS SET ON ATOM IS LAPW
> >>           E( 2)=    2.3500   E(BOTTOM)=    2.350   E(TOP)= -200.000
> >>              APW+lo
> >>           E( 2)=    1.0000
> >>              LOCAL ORBITAL
> >>           E( 0)=    0.3000
> >>              APW+lo
> >>           E( 1)=    0.3000
> >>              APW+lo
> >> 
> >>           ATOMIC SPHERE DEPENDENT PARAMETERS FOR ATOM  Ga5       
> >>           OVERALL ENERGY PARAMETER IS    0.3000
> >>           OVERALL BASIS SET ON ATOM IS LAPW
> >>           E( 2)=    1.6100   E(BOTTOM)=    1.610   E(TOP)= -200.000
> >>              APW+lo
> >>           E( 2)=    1.0000
> >>              LOCAL ORBITAL
> >>           E( 0)=    0.3000
> >>              APW+lo
> >>           E( 1)=    0.3000
> >>              APW+lo
> >> 
> >>           ATOMIC SPHERE DEPENDENT PARAMETERS FOR ATOM  Ga6       
> >>           OVERALL ENERGY PARAMETER IS    0.3000
> >>           OVERALL BASIS SET ON ATOM IS LAPW
> >>           E( 2)=    0.3400   E(BOTTOM)=    0.210   E(TOP)=    0.470
> >>              APW+lo
> >>           E( 2)=    1.0000
> >>              LOCAL ORBITAL
> >>           E( 0)=    0.3000
> >>              APW+lo
> >>           E( 1)=    0.3000
> >>              APW+lo
> >> 
> >>        K=   0.06250   0.06250   0.50000            1
> >> :RKM  : MATRIX SIZE 3918LOs: 168  RKM= 7.00  WEIGHT= 4.00  PGR:    
> >>        EIGENVALUES ARE:
> >>         -2.9833287   -2.9033434   -2.8711489   -2.8623625   -2.7906554
> >>         -2.7762807   -2.7674714   -2.5528370   -2.4163669   -2.3959290
> >>         -2.3743166   -2.3030169   -2.2624883   -1.9394406   -1.9244714
> >>         -1.8911925   -1.8833915   -1.8101535   -1.7608643   -1.7470634
> >>         -1.7139419   -1.6932904   -1.5676893   -1.5377474   -1.5116763
> >>         -1.5052158   -1.4501798   -1.4001378   -1.3946959   -1.3802247
> >>         -1.3524068   -1.3043611   -1.2374109   -1.1504261   -1.1233582
> >>         -1.0930868   -1.0755032   -1.0642763   -1.0264128   -0.9528169
> >
> >>            11 EIGENVALUES BELOW THE ENERGY   -3.00000
> >>        ********************************************************
> >> 
> >>            11 EIGENVALUES BELOW THE ENERGY   -3.00000
> >>        NUMBER OF K-POINTS:            16
> >>    
> >>  
> >> 
> >> _______________________________________________
> >> Wien mailing list
> >> Wien at zeus.theochem.tuwien.ac.at
> >> http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien
> >> 
> >
> >
> >                                      P.Blaha
> >--------------------------------------------------------------------------
> >Peter BLAHA, Inst.f. Materials Chemistry, TU Vienna, A-1060 Vienna
> >Phone: +43-1-58801-15671             FAX: +43-1-58801-15698
> >Email: blaha at theochem.tuwien.ac.at    WWW: http://info.tuwien.ac.at/theochem/
> >--------------------------------------------------------------------------
> >_______________________________________________
> >Wien mailing list
> >Wien at zeus.theochem.tuwien.ac.at
> >http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien
> 
> = = = = = = = = = = = = = = = = = = = =
> 			
> 
>         ?
> ?!
>  
> 				 
>         liyh
>         lyhua at fudan.edu.cn
>           2006-04-06
> 
> 


                                      P.Blaha
--------------------------------------------------------------------------
Peter BLAHA, Inst.f. Materials Chemistry, TU Vienna, A-1060 Vienna
Phone: +43-1-58801-15671             FAX: +43-1-58801-15698
Email: blaha at theochem.tuwien.ac.at    WWW: http://info.tuwien.ac.at/theochem/
--------------------------------------------------------------------------


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