[Wien] Problem with Energy Separation in LAPW2

[D.A. Tompsett]

Dear All,

I am trying to run a supercell calculation of transition metals in a Laves 
AB2 type phase. The supercell contains 96 atoms and one atom of type B 
doped onto the site of an A atom.

My calculation is repeatedly failing in LAPW2 and the stderr shows a QTL-B 
error. My case.scf2 looks like:
:GMA  : POTENTIAL AND CHARGE CUT-OFF  12.00 Ry**.5
         Bandranges (emin - emax) and occupancy:
:BAN00653: 653    0.928680    0.936548  1.99986482
:BAN00654: 654    0.929430    0.937439  1.98611648
:BAN00655: 655    0.930004    0.938320  1.90309467
:BAN00656: 656    0.930649    0.939398  1.26292794
:BAN00657: 657    0.931578    0.941737  0.87538741
:BAN00658: 658    0.932537    0.943451  0.57797216
:BAN00659: 659    0.933446    0.944369  0.30357104
:BAN00660: 660    0.934302    0.946221  0.06424059
:BAN00661: 661    0.934880    0.947167  0.02244603
:BAN00662: 662    0.935266    0.948367  0.00429503
:BAN00663: 663    0.935998    0.949509  0.00008381
:BAN00664: 664    0.937163    0.950250  0.00000000
:BAN00665: 665    0.938020    0.952270  0.00000000
:BAN00666: 666    0.939497    0.953069  0.00000000
:BAN00667: 667    0.941145    0.954260  0.00000000
:BAN00668: 668    0.941414    0.956103  0.00000000
        Energy to separate low and high energystates: -999.00000


:NOE  : NUMBER OF ELECTRONS          =1313.000

:FER  : F E R M I - ENERGY(TETRAH.M.)=   0.93629


The file stops there and gives no more information about the QTL-B error. I 
have tried changing the linearization energies to move them nearer the 
Fermi level. This has had no effect.

There seems to be something wrong with the line "Energy to separate low and 
high energystates: -999.00000". I have not been able to find out what this 
means, but suspect that it means that lapw2 could not find the gap between 
semi-core and valence states.

Can anyone suggest to me how I might fix this problem or where I should 
look to solve it?

Many thanks,
David Tompsett.

-- 
David A. Tompsett
Quantum Matter Group
Cavendish Laboratory
J. J. Thomson Avenue
Cambridge CB3 0HE
U.K.
Tel: +44 7907 566351 (mobile)
Fax: +44 1223 337351
http://www-qm.phy.cam.ac.uk/