[Wien] QTL-B and "Eigenvalues Below..."

[Stefaan Cottenier]

Hello again,

I have been too optimistic, yesterday. The reported problem  
("eigenvalues below...") did indeed disappear when I modified the  
sphere radii and/or put deep semi-core states in the core, as reported  
yesterday. But when I applied the same modification to a Cu atom at a  
different site in Ge (a case that was working well with the old  
settings), exactly the same problem now appeared there...

This happens, in the very first iteration, in a directory that was  
freshly initialized with not old files lingering around:

an error message in lapw2_3.error: 'l2main' - QTL-B.GT.15.,  
Ghostbands, check scf files

end of case.scf2_3 :

    QTL-B VALUE .EQ. **********   in Band of energy   -5.71041   ATOM=  
    5   L=  2
     Check for ghostbands or EIGENVALUES BELOW XX messages
     Adjust your Energy-parameters or use -in1new switch, check RMTs  !!!

But atom 5 (which is Ge) does not have states at that energy:

   0.30    4  0      (GLOBAL E-PARAMETER WITH n OTHER CHOICES, global APW/LAPW)
  2   -1.82      0.010 CONT 1
  2    0.30      0.000 CONT 1
  0    0.30      0.000 CONT 1
  1    0.30      0.000 CONT 1

The only other element in the cell is Cu (ATOM 1), which has these  
linearization energies:

   0.30    4  0      (GLOBAL E-PARAMETER WITH n OTHER CHOICES, global APW/LAPW)
  1    0.30      0.000 CONT 1
  1   -5.36      0.005 STOP 1
  2    0.30      0.010 CONT 1
  0    0.30      0.000 CONT 1

It looks like eigenstates for Cu and Ge are somehow interchanged by  
the error message...?

The end of case.scf1_3 :

:EIG00936:       1.9587652    1.9605022    1.9620300    1.9651681    1.9677904
:EIG00941:       1.9709236    1.9759120    1.9783975    1.9822565    1.9843245
:EIG00946:       1.9858109    1.9880890    1.9903135    1.9927309    1.9944311

:EIG00951:       1.9963998    1.9968078    1.9992533
             2 EIGENVALUES BELOW THE ENERGY   -9.00000
        ********************************************************

:KPT   :      NUMBER OF K-POINTS:     1

All other case.scf1_* files have "0 eigenvalues below". And these are  
the deepest eigenvalues in case.scf1:

:RKM  : MATRIX SIZE 5615LOs: 908  RKM= 6.53  WEIGHT= 8.00  PGR:
        EIGENVALUES ARE:
:EIG00001:      -4.9618775   -4.9618775   -4.9618749   -1.4433134   -1.4425104
:EIG00006:      -1.4425104   -1.4424955   -1.4415851   -1.4415851   -1.4414788
:EIG00011:      -1.4414788   -1.4414291   -1.4414284   -1.4412709   -1.4412709
:EIG00016:      -1.4411669   -1.4411669   -1.4410760   -1.4410224   -1.4409746

Here are the linearization energies that lapw1 determined (no in1new):

For Cu:


           ATOMIC SPHERE DEPENDENT PARAMETERS FOR ATOM  Cu1
:e__0001: OVERALL ENERGY PARAMETER IS    0.3000
           OVERALL BASIS SET ON ATOM IS LAPW
:E1_0001: E( 1)=    0.3000
              APW+lo
:E1_0001: E( 1)=   -4.9650   E(BOTTOM)=   -4.995   E(TOP)=   -4.935
              LOCAL ORBITAL
:E2_0001: E( 2)=   -0.0450   E(BOTTOM)=   -0.270   E(TOP)=    0.180
              APW+lo
:E0_0001: E( 0)=    0.3000
              APW+lo

For Ge:

           ATOMIC SPHERE DEPENDENT PARAMETERS FOR ATOM  Ge3
:e__0004: OVERALL ENERGY PARAMETER IS    0.3000
           OVERALL BASIS SET ON ATOM IS LAPW
:E2_0004: E( 2)=   -1.4450   E(BOTTOM)=   -1.530   E(TOP)=   -1.360
              APW+lo
:E2_0004: E( 2)=    0.3000
              LOCAL ORBITAL
:E0_0004: E( 0)=    0.3000
              APW+lo
:E1_0004: E( 1)=    0.3000
              APW+lo

I used RKMax=6.53 (Kmax=3.00), and 4 k-points -- values that should be  
more than good enough for reasonable results. Changing the initial  
linearization energies did not help to the values reported case.scf1  
did not help.

The real reason of this behaviour must lie elsewhere...?

Stefaan

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