[CP2K-user] How to testify the production species are radicals or not, during the MD simulation.

Vladimir Rybkin rybk... at gmail.com
Sun Apr 26 13:55:18 UTC 2020

Dear Du,

unfortunately, the plot is not clear to me. Why do reactant and product 
coexist? Do you have multiple reacting species in your cell? 

Anyway, if you purple is atom 143 and your green is atom 142, then what you 
get in the end has no spin polarisation: both spin populations are zero. 
So, you don't have radicals.



среда, 8 апреля 2020 г., 3:22:20 UTC+2 пользователь Du написал:
> Hi Vladimir,
> Thank you so much! I've noticed the Mulliken's shortage, so I'm wondering 
> whetther I can get the right information by qualitative estimate based on 
> the Mulliken. 
> Here are two figures. In first one, the green line is the react, the 
> purple line is the product. And the 142O 143O are the focused atoms(figure 
> 2). It shows, after dissociation, the 142O 143O have a spin moment peak, 
> though the value is small, but the contrast is obvious. Can it prove the 
> radical thing?
> 在 2020年4月6日星期一 UTC+8下午9:39:04,Vladimir Rybkin写道:
>> Dear Du,
>> in principle, population analysis will help, although Mulliken should be 
>> used with care. There are other options in CP2K as well, e.g. Hirshfeld, 
>> RESP. It may also be useful to print the spin density cube and analyse spin 
>> density distribution visually. 
>> It's not clear to me what the dissociation products are and which atoms 
>> in the output belong to them, but as far as I see, spin moments on all 
>> atoms are very small, i.e. there's no considerable spin polarisation. So, I 
>> would say you don't have radicals.
>> Yours, 
>> Vladimir
>> понедельник, 6 апреля 2020 г., 3:16:59 UTC+2 пользователь Du написал:
>>> Dear developers and users,
>>> Hello! I have a problem in my work, and I hope someone can give me some 
>>> guidance. My system is 40H2O + HSO5- + H+ + NGP, about 180 atoms. and I 
>>> focus on the HSO5- dissociation. Now the point is that I don't know whether 
>>> the dissociation product species are radicals or not. So I cut a piece of 
>>> the MD simulation when HSO5- gets dissociated, to do a single point energy 
>>> calculation in cp2k, with the mulliken polarization analysis. So my 
>>> question is, Can I figure out the species are radicals or not based on the 
>>> information in Mulliken polarization analysis? If it can, I attach the 
>>> Mulliken output profile, and I wonder how to use it? If not, What other 
>>> ways can I use to do it? 
>>> Thank you!
>>> Du 
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