How to specify the magnetic moment of each atom?

stclair leili... at gmail.com
Thu Feb 26 18:56:53 CET 2015


Got it. Thanks great!

On Thursday, February 26, 2015 at 11:51:15 AM UTC-6, S Ling wrote:
>
> For the warning message, you might neglect it if your calculation can 
> proceed. There was a recent post by Prof Juerg Hutter on that, just search 
> "ERRORL2 in qs_subsys_methods:num_ao_el_per_molecule" in the forum and you 
> should be able to find the post.
>
> SL
>
> On Thursday, February 26, 2015 at 4:55:18 PM UTC, stclair wrote:
>>
>> Hi, Matt,
>>
>> Thanks great for your helpful reply. I will give a try with 
>> 'CORE_CORRECTION.
>>
>> For the broken symmetry, I have tried it by setting the initial guess of 
>> the Ce atom as Ce3+ (only for the Ce atoms I want to localize the 
>> electrons). I attached the 'KIND' section for these Ce atoms. But I got the 
>> following error message:
>>  *************************************************************************
>>  *** 15:35:59 ERRORL2 in qs_subsys_methods:num_ao_el_per_molecule ::   ***
>>  *** SECOND SPIN CONFIG IS IGNORED WHEN MOLECULAR STATES ARE ASSIGNED! ***
>>  *************************************************************************
>> I checked the source file from 
>> http://cp2k.web.psi.ch/doxygen/trunk/de/d42/qs__subsys__methods_8f90_source.html. 
>> It seems due to the different initial guess for Alpha and beta and only 
>> Alpha will be used for calculation. Is that correct?
>> Could you help check if there is anything wrong in my setting?
>>
>> The basis set for Ce I am using is from a recent paper: JPCC, 2013, 117, 
>> 23082.
>>
>> Thanks great!
>>
>> Best,
>> Lei
>>
>>
>>
>> On Thursday, February 26, 2015 at 4:16:42 AM UTC-6, Matt W wrote:
>>>
>>> Hi,
>>>
>>> you can get what you are after by using the broken symmetry (&BS) 
>>> keyword within the &KIND block. It is a bit fiddly to use, but can be used 
>>> to specify the atomic guess used to generate the initial density matrix. 
>>> The are some threads in the forum and some stuff online if you look for it.
>>>
>>> But, my preferred way of _trying_ to localize the spins is to use the 
>>> &CORE_CORRECTION keyword, again in the &KIND section. So in this case pick 
>>> the two Ce that you want to localize the electrons onto and make them a new 
>>> kind in your geometry file (Ce3 or something). Then in &KIND Ce3 add 
>>> &CORE_CORRECTION 0.5 or 1.0.  This increases the effective nuclear charge 
>>> of these atoms and makes it very likely the electrons will localize on 
>>> them. You can then do a rough geometry relaxation to get the lattice 
>>> distortion that might stabilize the localized electrons. Then you can 
>>> restart but setting the &CORE_CORRECTION back to 0.0. If you are using an 
>>> appropriate density functional then you have a decent chance of getting the 
>>> localization you want. For the O vac in CeO2 you can just run a triplet 
>>> calculation with the modified core charge on a couple of Ce and you should 
>>> get what you want without bothering with the broken symmetry guess.
>>>
>>> Matt
>>>
>>> On Thursday, February 26, 2015 at 6:23:01 AM UTC, stclair wrote:
>>>>
>>>> Dear CP2K user,
>>>>
>>>>     I am working on CeO2 (111) surface with oxygen vacancy. Based on 
>>>> the previous studies, two extra electrons should locate on two next-nearest 
>>>> Ce atoms (as shown in the attached pictures). But my calculation converges 
>>>> to a different electronic configuration where the extra electrons locate on 
>>>> the Ce atoms closest to vacancy. Is there any keywords I can use to specify 
>>>> the magnetic moment for the atoms? Some keywords are similar to MAGMOM in 
>>>> VASP?
>>>>
>>>>    Thanks in advance.
>>>>
>>>> Best,
>>>> Lei
>>>>
>>>
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