Dear Prof. Postnikov,

I have found the swith *MullikenInSCF, thank you all the same*.

Best,

On Mon, Jul 26, 2010 at 9:43 PM, Bin Shao <[email protected]> wrote:

> Dear Prof. Postnikov,
>
> I set WriteMullikenPop 1 and I can check the Mulliken charges following the
> instruction in your lecture after the calculation finished. I found the
> magnetic moment raise from the 3d electrons in the Fe atom as expect.
>
> But I still don't know how to check the Mulliken charges when the job is
> running and further judge the convergence of the calculation, since I can
> not find anything about the Mulliken charges in the output file in the
> process.
>
> Thank you in advance!
>
> Best regards,
>
>
> On Mon, Jul 26, 2010 at 4:23 PM, Bin Shao <[email protected]> wrote:
>
>> Dear Prof. Postnikov,
>>
>> Thank you for your suggestion and the excellent lecture is what I need
>> now, thank you very much!
>>
>> Best regards,
>>
>>
>> On Mon, Jul 26, 2010 at 3:35 PM, <[email protected]> wrote:
>>
>>>
>>> >
>>> >>it is normal that as you increase your system to include many
>>> >> >equivalent (or almost) atoms
>>> >
>>> > I do not understand why many equivalent atoms will affect the
>>> convergence.
>>>
>>> Hi,
>>>
>>> I explained it already:
>>> >> because of electrons flopping between nearly degenerate states.
>>> In other words, the states just under the Fermi energy can be
>>> occupied in different way, and the electrons are just shifted around,
>>> without reaching the convergence.
>>>
>>> >>To get an idea, look at the results (Mulliken charges; DOS)
>>> >> >underway, after some number of iterations.
>>> >
>>> > Could you give me some ditails about checking the results of Mulliken
>>> > charges or DOS after some number of iterations?
>>>
>>> You print out Mulliken charges, there is a switch for it.
>>> You look at them and think whether they are as you expect
>>> (i.e., the atoms which ought to be magnetic are magnetic,
>>> and in a right way).
>>> Check if you find anything useful in the following lecture:
>>>
>>> http://www.home.uni-osnabrueck.de/apostnik/Lectures/APostnikov-Magnets.pdf
>>>
>>> > Usually, I just check the following information of the scf.
>>>
>>> >---------------------------------------------------------------------------
>>> > siesta: iscf   Eharris(eV)      E_KS(eV)   FreeEng(eV)   dDmax  Ef_up
>>> > Ef_dn(eV)
>>> >  ......
>>> > siesta:  799   -32180.0924   -32180.0919   -32180.0919  0.0011  -3.0670
>>> > -3.0670
>>> > siesta:  800   -32180.0924   -32180.0919   -32180.0919  0.0011  -3.0670
>>> > -3.0670
>>> ...
>>> > siesta:  826   -32180.0929   -32180.0925   -32180.0925  0.0010  -3.0669
>>> > -3.0669
>>> > siesta:  827   -32180.0931   -32180.0927   -32180.0927  0.0010  -3.0668
>>> > -3.0668
>>> > ......
>>>
>>> This is good but does not tell you anything but that your calculation
>>> is not quite converged.
>>> In fact it doesn't look like a divergence, and the Fermi level(s) are
>>> not a priori unreasonable. So, before doing anything else, try
>>> to make sense out of your calculation (position of bands, magnetic
>>> moments, etc.)
>>>
>>>
>>> ----------------------------------------------------------------------------
>>> >
>>> > I'd like to increase the DM.MixingWeight to 0.3 to accelerate the
>>> > calculation. Is it correct?
>>>
>>> If it smoothly converges to a right solution, that's fine.
>>> But I'd rather suggest, with system as large as yours, to be
>>> more prudent. 0.3 is a huge mixing weight.
>>>
>>> > Since you said I need a small mixing
>>> > parameter,
>>> > how to understand the mixing parameter? I read some notes about
>>> > DM.MxingWeight, but there is still something puzzled me.
>>> >
>>> > alpha has to be small (0.1-0.3) for insulator and semiconductors,
>>> > tipically much smaller for metals.
>>>
>>> Yes; what is the problem? In metals you need a good sampling of states
>>> near the Fermi level; imagine you have a narrow band which shifts
>>> across the E_f; then you'd like to damp the resulting fluctuations.
>>> In semiconductors the situation is (usually) less critical because
>>> bands are either occupied or empty.
>>>
>>> > BTW, whether my setting of the antiferromagnetism is correct.
>>>
>>> I don't know the structure, sorry. Apart from this - yes;
>>> some Fe atoms marked "+" and others "-", as it should be.
>>>
>>> Best regards
>>>
>>> Andrei Postnikov
>>>
>>>
>>
>>
>> --
>> Bin Shao
>> College of Information Technical Science, Nankai University
>> 94 Weijin Rd. Nankai Dist. Tianjin 300071, China
>> Email: [email protected]
>>
>
>
>
> --
> Bin Shao, Ph.D. Candidate
>
> College of Information Technical Science, Nankai University
> 94 Weijin Rd. Nankai Dist. Tianjin 300071, China
> Email: [email protected]
>



-- 
Bin Shao, Ph.D. Candidate
College of Information Technical Science, Nankai University
94 Weijin Rd. Nankai Dist. Tianjin 300071, China
Email: [email protected]

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