[Wien] QTL-B and "Eigenvalues Below..."
Stefaan Cottenier
stefaan.cottenier at fys.kuleuven.be
Thu Aug 14 12:01:48 CEST 2008
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:
2.ATOM Ge1 7 CORE STATES
CORE-FORCE in mRy/a.u. = |F| Fx Fy Fz
:FCO002: 2.ATOM 1.042 0.438 0.945
0.000
:1S 002: 1S -804.692384118 Ry
:2S 002: 2S -100.089338022 Ry
:2PP002: 2P* -88.948124153 Ry
:2P 002: 2P -86.605547718 Ry
:3S 002: 3S -11.686854428 Ry
:3PP002: 3P* -8.014357627 Ry
:3P 002: 3P -7.700089629 Ry
There were no 'Eigenvalues below' warnings in case2.output1_4, nor in
any of the other output1_* files:
==> case2.output1_4 <==
1.9738566 1.9763199 1.9777164 1.9875908 1.9885665
1.9893026 1.9912437
0 EIGENVALUES BELOW THE ENERGY -10.00000
********************************************************
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