[Wien] Different Rmt's for atoms of one type

Thu Apr 21 17:47:38 CEST 2011

Unfortunately I haven't got the SRC_RMTCheck in my WIEN2k install dir, 
maybe because I use 8.3 version. Could you please send it to me or 
publish on the WIEN2k web site?

Thanks,
Maxim

21.04.2011 21:39, Laurence Marks пишет:
> No, SRC_RMTCheck (search for RMTCheck). If you cannot find it, let me
> know -- I have to teach in a few minutes...
>
> 2011/4/21 Maxim Rakitin<rms85 at physics.susu.ac.ru>:
>> Thank you Laurence and Evgenia,
>>
>> Laurence, do you mean x_lapw script which attached to 2 emails in the
>> mailing list?
>> 1) [Wien] severe bug in x_lapw by Peter Blaha on 22.06.2010 2:03.
>> 2) Re: [Wien] LAPW2 crashed in parallel mode by Peter Blaha on 01.07.2010
>> 16:09.
>>
>> Thanks a lot for your help.
>> Maxim
>>
>> 21.04.2011 19:57, Евгения Каблиман пишет:
>>
>> Maxim, perhaps, you are interesting in calculation of the formation
>> energies.
>> And therefore, I am personally not sure, how is then better (and correct) to
>> estimate this value when Fe atoms have different RMT's in one supercell.
>> As Laurence very well explained, when "you use different RMTs for the Fe in
>> effect you make them different".
>>
>> 2011/4/21 Laurence Marks<L-marks at northwestern.edu>
>>> An approximate explanation, but first a caveat: dealing with small
>>> RMT's in Wien2k is not completely trivial.
>>>
>>> In Wien2k you have two different basis sets, a radial grid + orbitals
>>> inside the RMT, plane waves outside. If you use different RMTs for the
>>> Fe in effect you make them different. For instance, try setting up a
>>> Fe cell with two different RMTs (i.e. a supercell), converge it then
>>> do aim. You will find that there has been a small charge transfer
>>> between the Fe's, which will go to zero as you increase RKMAX.
>>>
>>> For your problem, I would go beyond setrmt (which is OK, but not
>>> always optimal) and use a smaller RMT for the C (maybe 1.3) and
>>> increase that for the Fe. You will have to do this by hand. Be careful
>>> about going too small with the C as if you do you will lose core
>>> charge (although .lcore helps); you also need to be careful about
>>> losing core electrons from the Fe. In both cases look in case.outputm
>>> to see how far the core integrals are from integers. Scale RKMAX so
>>> RKMAX/min(RMT) is roughly the same (e.g. 3.5), although you need to
>>> add a bit when you decrease the RMTs. Probably something like 5-6
>>> should be good for your problem.
>>>
>>> How to chose the "right" RMTs? I don't have any great wisdom, others
>>> might have. I tend to use RMTCheck (look in the mailing list, or I can
>>> ask Peter to add it to the contributed software) and check that the
>>> step in the gradients at the RMT for the different atoms are
>>> comparable. In most cases this gives results similar to setrmt. In
>>> principle you can also do calculations for different values with
>>> RKMAX/min(RMT) fixed and look for the minimum energy -- the few times
>>> I've done this the results are about the same. Another method would be
>>> to try and balance the charge lost in the core integrals, which gives
>>> a similar result.
>>>
>>> 2011/4/21 Maxim Rakitin<rms85 at physics.susu.ac.ru>:
>>>> Thank you Evgenia,
>>>>
>>>> I've already seen that link, but I'd like to get information why it is
>>>> not
>>>> possible from physical point of view.
>>>>
>>>> Maxim
>>>>
>>>> 21.04.2011 16:53, Евгения Каблиман пишет:
>>>>
>>>> Dear Maxim,
>>>>
>>>> identical elements should have identical RMT's.
>>>> This link might help you http://www.wien2k.at/reg_user/faq/rmt.html .
>>>>
>>>> 2011/4/21 Maxim Rakitin<rms85 at physics.susu.ac.ru>
>>>>> Dear WIEN2k community,
>>>>>
>>>>> Is it correct to perform calculations with different Rmt radii for
>>>>> atoms
>>>>> of one type, e.g. Fe?
>>>>>
>>>>> I need to calculate total energy of a systems containing one
>>>>> interstitial
>>>>> carbon atom in bcc iron matrix. Carbon has quite large MT-radius
>>>>> comparing
>>>>> with H atom, so StructGen sets Rmt(Fe) to 1.59 a.u. and Rmt(C) to 1.41
>>>>> a.u.
>>>>> for lattice constant 5.394 a.u. In some papers (C. Domain et al., PRB
>>>>> 69,
>>>>> 144112 (2004)) Rmt(C) is even large than I got (~1.6 a.u.) and Rmt(Fe)
>>>>> is
>>>>> also much larger (~2.4 a.u.). But if I use the radii from the article,
>>>>> WIEN2k doesn't allow me to perform further procedures - nn gives me
>>>>> information about overlapping spheres.
>>>>>
>>>>> Can I use Rmt(Fe)=2.4 a.u. in all volume of my supercell except of the
>>>>> nearest iron atoms?
>>>>>
>>>>> Thanks in advance for your answers.
>>>>>
>>>>> --
>>>>> Best regards,
>>>>>    Maxim Rakitin
>>>>>    South Ural State University
>>>>>    Chelyabinsk, Russia
>>>>>    email: rms85 at physics.susu.ac.ru
>>>>>    web: http://www.susu.ac.ru
>>>>>
>>>>> _______________________________________________
>>>>> Wien mailing list
>>>>> Wien at zeus.theochem.tuwien.ac.at
>>>>> http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien
>>>>
>>>>
>>>> --
>>>> Evgeniya Kabliman.
>>>> Insitute of Materials Chemistry         Vienna University of Technology
>>>> Getreidemarkt 9/165-TC, A-1060 Vienna, Austria
>>>> Tel: +43 1 58801 15674        Fax: +43 1 58801 15698
>>>> evgeniya at theochem.tuwien.ac.at            http://www.imc.tuwien.ac.at
>>>>
>>>> _______________________________________________
>>>> Wien mailing list
>>>> Wien at zeus.theochem.tuwien.ac.at
>>>> http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien
>>>>
>>>> _______________________________________________
>>>> Wien mailing list
>>>> Wien at zeus.theochem.tuwien.ac.at
>>>> http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien
>>>>
>>>>
>>>
>>>
>>> --
>>> Laurence Marks
>>> Department of Materials Science and Engineering
>>> MSE Rm 2036 Cook Hall
>>> 2220 N Campus Drive
>>> Northwestern University
>>> Evanston, IL 60208, USA
>>> Tel: (847) 491-3996 Fax: (847) 491-7820
>>> email: L-marks at northwestern dot edu
>>> Web: www.numis.northwestern.edu
>>> Chair, Commission on Electron Crystallography of IUCR
>>> www.numis.northwestern.edu/
>>> Research is to see what everybody else has seen, and to think what
>>> nobody else has thought
>>> Albert Szent-Gyorgi
>>> _______________________________________________
>>> Wien mailing list
>>> Wien at zeus.theochem.tuwien.ac.at
>>> http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien
>>
>>
>> --
>> Evgeniya Kabliman.
>> Insitute of Materials Chemistry         Vienna University of Technology
>> Getreidemarkt 9/165-TC, A-1060 Vienna, Austria
>> Tel: +43 1 58801 15674        Fax: +43 1 58801 15698
>> evgeniya at theochem.tuwien.ac.at            http://www.imc.tuwien.ac.at
>>
>> _______________________________________________
>> Wien mailing list
>> Wien at zeus.theochem.tuwien.ac.at
>> http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien
>>
>> _______________________________________________
>> Wien mailing list
>> Wien at zeus.theochem.tuwien.ac.at
>> http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien
>>
>>
>
>