The ABINIT Users Mailing List ( CLOSED )

["Chun Li" <lichun79@163.com>]

Dear Prof. Vanderbilt and Prof. Gonze,

Thanks a lot for your responses.
Do you mean I must modify the berryphase subroutine (I found the 
berryphase_new.F90 on the web) before performing the calculations? Frankly, I 
do not specialize in physics, but I really want to make some modifications to 
overcome the problem. I have read the papers of Vanderbilt and Resta focus on 
the modern polarization theory and Berry phase. Could you give me more 
references about the present problem?

Thank you again.

Chun

----- Original Message ----- 
From: "David Vanderbilt" <dhv@physics.rutgers.edu>
To: <forum@abinit.org>
Sent: Thursday, September 21, 2006 12:58 AM
Subject: Re: [abinit-forum] polarizations using Berry phase method


> Dear Chun Li,
> 
> You also might find this paper helpful in thinking about the problem:
> 
>   http://arxiv.org/abs/cond-mat/0511042
> 
> It goes into more detail about Wannier functions than you probably
> need, but it more or less confirms that the idea of having a
> well-defined polarization along the z axis is a reasonable one.
> 
> David V.
> 
> On Wed, 20 Sep 2006, Xavier Gonze wrote:
> 
>>
>> On 19 Sep 2006, at 05:58, Chun Li wrote:
>>
>>> Dear all,
>>> 
>>> I want to perform polarization calculations on ZnO nanofilms. After 
>>> ground-state calculations, I found that the slabs are metallic, which is 
>>> consistent with the previous research work. But in the direction 
>>> perpendicular to the slab, the system is insulating indeed. So I wonder 
>>> if 
>>> I can use the Berry phase method implemented in ABINIT to calculate the 
>>> polarizations only in this direction. Any ideas or suggestions are 
>>> appreciated.
>>> 
>>> Thank you and best regards.
>>> 
>>> Chun
>>> 
>>
>> Dear Chun Li,
>>
>> On the level of principles, I think that the idea is valid. However, I 
>> think 
>> that
>> you have to hack ABINIT to do the calculation, because you need to take
>> into account the occupation numbers for the summation of Berry phase
>> contributions in the Berry phase routine, and this is not done...
>>
>> If you succeed to do the modifications, we would be glad to include them !
>>
>> Xavier
> 
> ------------------------------------------------------------------------
> Prof. David Vanderbilt               Phone: (732) 445-2514
> Department of Physics and Astronomy  Fax:   (732) 445-4400
> Rutgers University                   Email:  dhv@physics.rutgers.edu
> 136 Frelinghuysen Road               http://www.physics.rutgers.edu/~dhv
> Piscataway, NJ 08854-8019   USA
> ------------------------------------------------------------------------
> 
>