[Wien] QTL-B and "Eigenvalues Below..."
Peter Blaha
pblaha at theochem.tuwien.ac.at
Thu Aug 14 14:26:28 CEST 2008
Seems to be a difficult and strange situation. I've met that before only one a
very few cases. I'm NOT surprised that the problems happen only for a certain
k-point, that was also in my cases.
Definitely the -in1new case needs some changed eseper-parameters (in2c), so that it does
not separate sc-valence at the wrong "gap" (between s-p statees), but between
d - sp; leading to
> .13832 5 0 global e-param with N other choices, napw
> 0 -0.124 0.000 CONT 1 -------------->too
> 0 -0.421 0.000 CONT 1 -------------->close
> 1 0.129 0.000 CONT 1
> 2 0.106 0.000 CONT 1
> 2 -1.464 0.000 CONT 1
The second case is more difficult to explain. The output clearly says the ghostbands
have "d" (L=2) character. I don't think it has anything to do with core-energies,...
Since to my knowledge there was hardly a code change in the relevant sections, but
it seems that such problems occur more often only quite recently, I've a new guess:
It could be a strange numerical problem of the matrix diagonalization, and I've even
some suspicions that it is due to the newer versions of the MKL-lib.
If you like, you may send me a tar file (to private email) with struct, clmsum, input
files and I'll have a look on it.
Regards
Stefaan Cottenier schrieb:
> Dear wien2k community,
>
> I want to come back to this thread, as I did not yet succeed to identify
> what is really going on.
>
> To summarize the original problem: a crash in lapw2 for impurities in
> Ge, with very large (actually ******) QTL-B warnings and (sometimes)
> "Eigenvalues below" warnings in the preceding case.output1.
>
> Earlier suggestions from the mailing list: keep Ge-3p in the core, take
> larger sphere sizes for Ge. This helps in some cases, but then the
> problem reappears in very similar cases that were before running without
> problem.
>
> I have now 2 test cases that show the problem, and that are as simple
> and clean as possible. Both are a 64-atom supercell of pure bulk Ge (no
> impurities), with the symmetry artificially lowered such that there are
> 10 inequivalent positions. This is the diamond structure, with 4.71 au
> between nearest neighbours. What I call case1 has Rmt=2.29 and RKM=8.01
> for all Ge atoms (Kmax=3.5), case2 has Rmt=2.34 and RKM=8.19 (again
> Kmax=3.5). Ge-3p states are in the core, sphere sizes are larger than in
> my previous post, and there is now only one element involved (Ge). In
> case1, -in1new is used, in case2 not. I discuss both these cases
> independently. They give more or less the same errors, although some
> details of the errors are different.
>
> I do not succeed to reproduce this error in a smaller cell (e.g. the
> 2-atom unit cell for the diamond structure). And it looks like the
> problem is connected to the basis set size: often a small basis set
> works (Kmax=2.5), but the problem appears when going to larger basis
> sets as the Kmax=3.5 from the following two examples.
>
> Any hints on what is going wrong?
>
> Thanks,
> Stefaan
>
> ----------------
> Case1
> ----------------
> This case (Rmt=2.29, RKM=8.01) was restored from a previous run, that
> successfully finished at RKM=8.01 and without in1new. The only thing
> that was changed for the present run, was to add -in1new 1. It crashes
> right in the first iteration, with this error in case1.output2_4 (no
> errors in the other 3 parts of this k-point parallel run):
>
> QTL-B VALUE .EQ. 1844.97972 in Band of energy -9.34906 ATOM=
> 5 L= 2
> Check for ghostbands or EIGENVALUES BELOW XX messages
> Adjust your Energy-parameters or use -in1new switch, check RMTs !!!
>
> There are no eigenvalues around -9.3 Ry, however, as can be seen in the
> last iteration of the successful preceding run without -in1new:
>
> K= 0.12500 0.12500 0.12500 1
> :RKM : MATRIX SIZE 8335LOs: 896 RKM= 8.01 WEIGHT= 8.00 PGR:
> EIGENVALUES ARE:
> :EIG00001: -1.4769260 -1.4769260 -1.4769260 -1.4769258
> -1.4769257
> :EIG00006: -1.4769257 -1.4767479 -1.4767478 -1.4767478
> -1.4766416
> :EIG00011: -1.4766416 -1.4766416 -1.4766414 -1.4766414
> -1.4766414
> (--snip--)
>
> This -9.3 Ry rather lies in the region of the core state energies:
>
> 5.ATOM Ge4 7 CORE STATES
> CORE-FORCE in mRy/a.u. = |F| Fx Fy Fz
> :FCO005: 5.ATOM 0.004 0.000 -0.004
> 0.000
>
> :1S 005: 1S -804.696867125 Ry
> :2S 005: 2S -100.093011168 Ry
> :2PP005: 2P* -88.951919057 Ry
> :2P 005: 2P -86.609329514 Ry
> :3S 005: 3S -11.689696508 Ry
> :3PP005: 3P* -8.017205664 Ry
> :3P 005: 3P -7.702933865 Ry
>
> In the crashed iteration, there is an 'eigenvalues below' warning in
> case1.output1_4 (not in the other 3 output1_* files):
>
> 1.9669005 1.9677156 1.9730728 1.9808975 1.9813078
> 1.9815618 1.9971970 1.9973338 1.9984643
> 1 EIGENVALUES BELOW THE ENERGY -10.00000
> ********************************************************
>
> The automatically produced case1.in1c looks like this (only one atom
> shown, all other are identical to this):
>
> .13832 5 0 global e-param with N other choices, napw
> 0 -0.124 0.000 CONT 1
> 0 -0.421 0.000 CONT 1
> 1 0.129 0.000 CONT 1
> 2 0.106 0.000 CONT 1
> 2 -1.464 0.000 CONT 1
>
>
> ----------------
> Case2
> ----------------
> This case (Rmt=2.34, RKM=8.19) was started from scratch and fails in the
> 20th iteration. In contrast to case1, no -in1new was ever used.
>
> These are the first few eigenvalues in the last successful iteration (we
> will need them later):
>
> K= 0.12500 0.12500 0.12500 1
> :RKM : MATRIX SIZE 8335LOs: 896 RKM= 8.18 WEIGHT= 8.00 PGR:
> EIGENVALUES ARE:
> :EIG00001: -1.4742860 -1.4742754 -1.4742754 -1.4742486
> -1.4742368
> :EIG00006: -1.4742368 -1.4740887 -1.4740887 -1.4740748
> -1.4739971
> :EIG00011: -1.4739788 -1.4739788 -1.4739514 -1.4739514
> -1.4739368
> :EIG00016: -1.4737167 -1.4736918 -1.4736918 -1.4736907
> -1.4736581
> (--snip--)
>
> All Ge atoms show the expected linearization energies in case.scf:
>
> ATOMIC SPHERE DEPENDENT PARAMETERS FOR ATOM Ge8
> :e__0009: OVERALL ENERGY PARAMETER IS 0.3000
> OVERALL BASIS SET ON ATOM IS LAPW
> :E2_0009: E( 2)= -1.4700 E(BOTTOM)= -1.520 E(TOP)= -1.420
> APW+lo
> :E2_0009: E( 2)= 0.3000
> LOCAL ORBITAL
> :E0_0009: E( 0)= 0.3000
> APW+lo
> :E1_0009: E( 1)= 0.3000
> APW+lo
>
> And this is a part from the case2.in1c file which was used:
>
> 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
>
> Now come the error messages:
>
> In case2.output2_4 (all other 3 parts of this parallel run are OK), the
> last lines are:
>
> QTL-B VALUE .EQ. ********** in Band of energy -8.74304 ATOM=
> 5 L= 2
> Check for ghostbands or EIGENVALUES BELOW XX messages
> Adjust your Energy-parameters or use -in1new switch, check RMTs !!!
>
> As you see from the eigenvalues printed above, there are no eigenvalues
> in this energy range. It looks like somehow a core state is taken to be
> a valence state...? These are the core state energies from the last
> succesful iteration:
>
--
P.Blaha
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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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