[Wien] Lapw1 error
EB Lombardi
lombaeb at science.unisa.ac.za
Fri May 13 10:27:53 CEST 2005
Dear Prof Blaha
Thank you for your comments - dropping the P 2s LO works.
From this solution and the new discussion in the QTL-B FAQ, I have two
more questions:
1. How can one know "a priori" when it is possible to drop an
automatically generated LO without adversly affecting the accuracy of
the calculation?
2. It seems the 2s/3s problem here was analogous to the 3p/4p example
discussed in the UG(12.1). In the FAQ it is mentioned that "you need to
remove a LO or increase the energy seperation between LO and L/APW
energies". Removing the LO works well; however if one were to increase
the energy separation between the LO and L/APW energies instead, I
assume it is the energy of the 2s LO that needs to be changed (increased
relative to the 'Global E parameter' for that atom?)
Does a general "prescription" exist on how to choose the expansion
energy of LO's?
Thank you
Regards
Enrico
Peter Blaha wrote:
>I tried your struct file and generated a default initialization.
>As you said, lapw2 crashes with:
>
>/tmp/phos> x lapw2 -c
>
>
>Input/Output Error 148: Invalid character
>
> In Procedure: outp
> At Line: 181
>
> Statement: Formatted READ
> Unit: 1010
> Connected To: ./phos.help040
> Form: Formatted
> Access: Sequential
>Records Read : 34
>Records Written: 0
>
>
>With this info one should check phos.help040 (at line 34)
>It contains the partial charges for atom 10 (help031 is atom 1,....)
>and from line 34 it is clear that P-s causes the problem.
>
>I could easily solve it by simply removing the LO for the s-state.
>
>(The problem is caused by the small spheres; 2s/3s problem)
>
>I've modified the faq-page on QTL-B problems to cover also this problem.
>
>
>
>>In all cases, I use a separation energy of -10 Ry in lstart to place the P-2p
>>in the valence as LO's (to prevent charge leakage, as you mentioned). Using
>>this approach the charge leakage is:
>>For P:
>>TOTAL CORE-CHARGE: 4.000000
>>TOTAL CORE-CHARGE INSIDE SPHERE: 3.995122
>>TOTAL CORE-CHARGE OUTSIDE SPHERE: 0.004878
>>For C atoms:
>>TOTAL CORE-CHARGE: 2.000000
>>TOTAL CORE-CHARGE INSIDE SPHERE: 1.999732
>>TOTAL CORE-CHARGE OUTSIDE SPHERE: 0.000268
>>
>>The leakage for P is still an order of magnitude larger than for C.
>>
>>The .in1c file contains (default input) for P:
>> 0.30 4 0 (GLOBAL E-PARAMETER WITH n OTHER CHOICES, global APW/LAPW)
>>1 0.30 0.000 CONT 1
>>1 -8.80 0.005 STOP 1
>>0 -0.79 0.010 CONT 1
>>0 0.30 0.000 CONT 1
>>
>>For the sake of completeness I am attaching the struct files, etc. which I
>>attached to the original e-mail.
>>
>>Note: for the 'plain' LAPW calculation mentioned in my previous e-mail (3.1),
>>the fermi level lies at 1.30409 Ry. So according to the FAQ, I also tried
>>replacing all '0.30' entries in .in1c with '1.00'. This does not solve the
>>problem either, but results in ghost bands at -2.2662 and -2.2663 Ry.
>>
>>Best regards
>>Enrico
>>
>>--
>>Dr E B Lombardi
>>Physics Department
>>University of South Africa
>>P.O. Box 392
>>0003 UNISA
>>South Africa
>>Tel: +27 (0)12 429-8027
>>Fax: +27 (0)12 429-3643
>>e-mail: lombaeb at science.unisa.ac.za
>>
>>
>>
>>
>>Peter Blaha wrote:
>>
>>
>>
>>>Just a guess:
>>>
>>>Have you checked for any core leakage of the P site ?
>>>Check case.outputst for corresponding WARNINGS.
>>>With such small spheres it might be that you need to decrease the -6.0 Ry
>>>core-valence seperation energy and include P-2p (maybe even 2s) states in
>>>the bandstructure. Otherwise the valence states are not strickly orthogonal
>>>to the core and this leads to ghostbands.
>>>
>>>
>>>
>>>
>>>>Dear Lyudmila and Wien authors.
>>>>
>>>>Regarding the previous 'ghost band' errors I mentioned in the previous
>>>>e-mails
>>>>on this topic:
>>>>
>>>>1. There has been an additional error in the APW calculation (using
>>>>unmodified .in1c) which I did not notice originally. In the scf files the
>>>>following suspicious lines occur:
>>>>QTL-B VALUE .EQ. ********** in Band of energy 0.00000
>>>>QTL-B VALUE .EQ. ********** in Band of energy 0.00000
>>>>Similarly for a mixed APW/LAPW run (see below):
>>>>QTL-B VALUE .EQ. 2.35833 in Band of energy 0.00000
>>>>QTL-B VALUE .EQ. 2.35913 in Band of energy 0.00000
>>>>
>>>>The problem is that there is no band of energy 0.00000.
>>>>
>>>>
>>>>2. I tried your suggestion of using a value of -0.2 Ry for the P_s LO
>>>>(using
>>>>APW). This results in a similar crash, with a ghost band at -1.307337 Ry.
>>>>(the original unmodified APW run had a ghost band at -3.34806 eV)
>>>>
>>>>3. I also tried several other combinations, none of which worked, as
>>>>follows:
>>>>
>>>>3.1: When using LAPW rather than APW for all atoms (default .in1c), the
>>>>SCF
>>>>cycles converge for the initial geometry structure only. However, when
>>>>using
>>>>"min -p -sp -s 1" for a geometry optimization, lapw2 crashes again in the
>>>>first SCF cycle of the new geometry, with many ghost bands at -0.39479,
>>>>-0.38044, +0.26593, +0.28952, +0.33388, +0.37419, +0.41470, .......... Ry
>>>>
>>>>3.2: When mixing LAPW for the P-s orbitals and APW for everything else,
>>>>the
>>>>results are similar to 3.1 with the SCF cycles converging for the initial
>>>>geometry, but crashing in the first SCF cycle of the second geometry
>>>>optimization step with ghost bands at +0.20051, +0.52656, +0.79082,
>>>>+1.25045
>>>>Ry.
>>>>
>>>>3.3 Changing sphere sizes: When using plain LAPW with default input, but
>>>>changing the sphere sizes (Rmt_C from 1.30au to 1.37au, Rmt_P from
>>>>1.42au to
>>>>1.40au), this results in a crash in the 5th SCF cycle of the initial
>>>>geometry
>>>>with a message of "FORTRAN STOP L2main - QTL-B Error".
>>>>This is an "improvement" since that lapw2 is able to stop with an error
>>>>message, rather than just crashing on the ******* in the *.help_ files.
>>>>The
>>>>QTL errors are not so large either. This case is rather perplexing since
>>>>the
>>>>sphere size of P was reduced, while the sphere sizes of the C atoms were
>>>>increased.
>>>>
>>>>For the 5th SCF cycle, the scf files contained:
>>>>phos.scf2dn: QTL-B VALUE .EQ. 6.99287 in Band of energy 0.15828
>>>>phos.scf2dn_1: QTL-B VALUE .EQ. 4.61602 in Band of energy
>>>>0.07087
>>>>phos.scf2dn_2: QTL-B VALUE .EQ. 4.55460 in Band of energy
>>>>0.63894
>>>>phos.scf2dn_3: QTL-B VALUE .EQ. 3.96843 in Band of energy
>>>>0.30243
>>>>phos.scf2dn_4: QTL-B VALUE .EQ. 6.99287 in Band of energy
>>>>0.15828
>>>>phos.scf2p: QTL-B VALUE .EQ. 6.99287 in Band of energy 0.15828
>>>>phos.scf2up_1: QTL-B VALUE .EQ. 5.72604 in Band of energy
>>>>0.05845
>>>>phos.scf2up_2: QTL-B VALUE .EQ. 5.74549 in Band of energy
>>>>0.62481
>>>>phos.scf2up_3: QTL-B VALUE .EQ. 4.91945 in Band of energy
>>>>0.28777
>>>>phos.scf2up_4: QTL-B VALUE .EQ. 7.45940 in Band of energy
>>>>0.14799
>>>>
>>>>Note: calculations of other impurities with the same small C spheres had
>>>>no
>>>>problems.
>>>>
>>>>Any suggestions would be welcome
>>>>
>>>>Best regards
>>>>
>>>>Enrico
>>>>
>>>>
>>>>Lyudmila Dobysheva wrote:
>>>>
>>>>
>>>>
>>>>
>>>>>Dear Enrico,
>>>>>
>>>>>So, the APW+lo makes the first density not good, as there appeared the
>>>>>level
>>>>>with -3.34 Ry. I have looked in my old calculations (pure phosphorus and
>>>>>alloys with phosphorus) and found that I was completely wrong: these
>>>>>phosphorus s-electrons should be in the valence band. I mixed them with
>>>>>P2s.
>>>>>The APW+lo calculation in the first iteration is wrong, the -0.79 which
>>>>>comes from the atomic density estimate is more correct. Now I think that
>>>>>it
>>>>>is just opposite to my first guess - too low, in my calculations the
>>>>>valence
>>>>>band starts at -0.2 Ry and these P s-electrons should lie there. The
>>>>>wrong
>>>>>linearization energy (too low!) gave a ghost at -3.34 Ry. The LAPW
>>>>>scheme
>>>>>has apparently a wider interval of energy where linearization works
>>>>>well,
>>>>>and does not give the ghost, and the APW+lo fails. So, I think that now,
>>>>>if
>>>>>you can calculate with the LAPW scheme, you can obtain a convergent
>>>>>calculation in it, and then try to continue with APW+lo. And as a test
>>>>>it
>>>>>would be very interesting to make a calculation APW+lo at -0.2 Ry or
>>>>>near,
>>>>>and look at the result, please write me the result - my settings of the
>>>>>system do not allow me to repeat calculation of your system quickly.
>>>>>By the way, I was using then:
>>>>>0.30 3 0 (GLOBAL E-PARAMETER WITH n OTHER CHOICES, global
>>>>>APW/LAPW)
>>>>>0 -0.79 0.010 CONT 0
>>>>>0 0.30 0.000 CONT 0
>>>>>1 0.30 0.000 CONT 1
>>>>>
>>>>>This is a good observation, I'll remember that sometimes APW+lo and LAPW
>>>>>may
>>>>>give such different results at the first stages.
>>>>>
>>>>>Best regards
>>>>>Lyudmila Dobysheva
>>>>>------------------------------------------------------------------
>>>>>Phys.-Techn. Institute of | Tel.(home): 7 (3412) 442118
>>>>>Ural Br. of Russian Ac. of Sci. | Tel.(office): 7 (3412) 218988
>>>>>426001 Izhevsk, ul.Kirova 132 | Fax: 7 (3412) 250614
>>>>>RUSSIA | E-mail: lyu at otf.fti.udmurtia.su
>>>>>------------------------------------------------------------------
>>>>>http://fti.udm.ru/ltt/personals/dobysh.htm
>>>>>------------------------------------------------------------------
>>>>>
>>>>>_______________________________________________
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>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
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>>>>
>>>>
>>>>
>>> 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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>>>
>>>
>
>
> 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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