The ABINIT Users Mailing List ( CLOSED )

[Samantha Jenkins <Samantha.Jenkins@htu.se>]

Dear Petr


> fhi98PP is the package for generating norm-conserving
> pseudopotentials (see abinit page for link, it is well documented).

OK thankyou.

> For the question of point properties - we have performed some study
> of these quantities (laplacian, rho, eigenvectors at BCP) in oxides.
> The numeric precision is rather good (even in laplacian) and the
> results seem to be comparable to the results based on the localised
> basis algorithms found in literature (at least for oxides). However,
> so far our interest was concetrated mainly to the integrated
> quantities.

That does sound promising, I am interested in nanotubes, so to summarise 
then I use fhi98PP to generate the carbon psuedopotential, presuming the 
bonds at the end of the tube need passivating, then I can get the point
properties from the charge density map that I get out of abinit.


Best wishes

 Samantha
>
>> Dear Petr
>>
>>
>>> I don't know if I have explained well the situation. In our
>>> analysis we use the valence electron density (calculated by
>>> Abinit) AND the core electron densities (for each type of atom)
>>> generated by the fhi98PP (i.e. the core density corresponding to
>>> the pseudopotentials used in the calcul=> *.fc). All these files
>>> give the density in the real space (valence density =>
>>> equidistant grid in elementary cellule, core density => radial
>>> logarithmic grid) and whole our analysis is then based on 3D
>>> interpolation in real space!!!
>>>
>>
>>
>> Ok, I did not know that it was OK to do this adding back in of core
>> charge.
>>
>>
>>> All what you need is the output density file *_DEN of abinit
>>> (valence) and the files *.fc (for all elements), generated
>>> together with your pseudopotentials by fhi98PP. The precision of
>>> the charge determined in this way is usually something about
>>> 0.003 electrons (even at the surfaces).
>>>
>>>
>>
>> What is fhi98PP that sounds like a DFT code ? How good is abinit
>> for properties at the BCP?, sounds very good for the integration
>> quantities but I am more  interested in the point properties at the
>> BCP.
>>
>> Best wishes
>>
>> Samantha J.
>>
>>
>>> Best wishes Petr Casek
>>>
>>>
>>>
>>>
>>>
>>>> Dear Petr,
>>>>
>>>> Thankyou for your prompt reply, I can see why you don't use
>>>> psuodopotentials with AIM since many people want to calculate
>>>> Bader charges etc.
>>>>
>>>> Can you calculate G and V at the BCP as well, (using localised
>>>> basis sets of course). So I will have to use localised basis
>>>> sets, I take it their is a library of these avaliable, are they
>>>> optimised for different envíroments. Is the format of these
>>>> basis sets similar to any other standard forms.
>>>>
>>>> Thanks again,
>>>>
>>>> Best wishes
>>>>
>>>> Samantha J.
>>>>
>>>>
>>>> Bader analysis is already implemented in 3.4 branche of Abinit
>>>> (see Release notes) as the postprocessing tool (aim). The short
>>>> help for the latter is in the Infos subdirectory (aimhelp.*).
>>>> With this tool it is possible to obtain all basic quantities of
>>>> Bader theory, i.e. Bader charge, critical points (with
>>>> eigenvalues and eigenvectors of Hessian), the volume of Bader
>>>> atom and of course Bader surface. So far we have not touched
>>>> the problem with the using of pseudopotentials in this analysis
>>>> (but you can always see in the output separate contributions of
>>>> core and valence electrons to the Bader charge and so estimate
>>>> possible problems)
>>>>
>>>> Best wishes Petr Casek
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>> Dear abinit users,
>>>>>
>>>>> I am new to abinit, can you tell me if abinit can be used to
>>>>> obtain AIM (atoms in molecules, Bader analysis) using
>>>>> psuedopotentials? I am looking for these quantities at the
>>>>> BCP (bond critical point) only? Such and rho and laplacian
>>>>> (rho) and the eigenvectors. I know that psuedopotentails and
>>>>> AIM are in principle OK as long as the psuopotential is not
>>>>> too hard core.
>>>>>
>>>>>
>>>>> Thanks for any advice,
>>>>>
>>>>> Best wishes
>>>>>
>>>>> Samantha J
>>>>>
>>>>>
>>>>>
>>>>
>>>> Dr. Samantha Jenkins                 H       Ph. +46 (0)520
>>>> 475318 Dept. of Informatics & Mathematics    \      Fax +46
>>>> (0)520 475399 University of Trollhattan/Uddevalla    O:
>>>> Samantha.Jenkins@htu.se P.O. Box 957, Trollhattan             /
>>>> S.Jenkins@physics.org SE 461 29 Sweden                     H
>>>>
>>>>
>>>>
>>>>
>>>
>>
>>
>>


--
Dr. Samantha Jenkins                 H       Ph. +46 (0)520 475318
Dept. of Informatics & Mathematics    \      Fax +46 (0)520 475399
University of Trollhattan/Uddevalla    O:    Samantha.Jenkins@htu.se
P.O. Box 957, Trollhattan             /      S.Jenkins@physics.org
SE 461 29 Sweden                     H