[Pw_forum] How to get atomic partial charge for MD

[Konstantin Kudin]

 By the way, is "naivebamboo" an actual name, or, at least, a nickname
? :-) 

 Anyways, back to the topic, since there is some value in answering
questions that might be of interest to others.

 QE can do Lowdin charges, which is another approximate way to do the
charge partitioning.

 There is an interesting option not currently implemented known as
"Bader Analysis" , so feel free to implement it if you find it might
help :

http://theory.cm.utexas.edu/bader/

 From the description of what this program needs, it might be
relatively easy to work with.

 Kostya


Quote from the above link:
"Many years ago, Richard Bader from McMaster University, developed an
intuitive way of dividing molecules into atoms. His definition of an
atom is based purely on the electronic charge density. Bader uses what
are called zero flux surfaces to divide atoms. A zero flux surface is a
2-D surface on which the charge density is a minimum perpendicular to
the surface. Typically in molecular systems, the charge density reaches
a minimum between atoms and this is a natural place to separate atoms
from each other.

Besides being an intuitive scheme for visualizing atoms in molecules,
Bader's definition is often useful for charge analysis. For example,
the charge enclosed within the Bader volume is a good approximation to
the total electronic charge of an atom. The charge distribution can be
used to determine multipole moments of interacting atoms or molecules.
Bader's analysis has also been used to define the hardness of atoms,
which can be used to quantify the cost of removing charge from an
atom."
 

 
 

--- naivebamboo Huang <naivebamboo at hotmail.com> wrote:

> Dear pwscf users,
>           I am trying to get effective atomic charges of Bi2Te3  and
> apply 
> them in my molecular dynamics simulation. Does any one know how to
> get this? 
> I recognize that the definition of partial charge is arbitrary since
> the 
> boundary of electron density is not distinct. I would like to know
> which 
> kinds of partial charge can be obtained in PWSCF except Born charge.
> I was 
> told that the charges derived from effective electrostatic potential
> (ESP) 
> might be the most appropriate for MD calculation. I don't if I could
> get the 
> effective electrostatic potential since ESP normally is obtained in
> Wan der 
> Waals regimes, which may be not applicable for crystals.
>       Any help will be greatly appreciated.
> 
> Thanks very much
> 
> Baoling Huang
> 
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