QuantumATK Forum

QuantumATK => General Questions and Answers => Topic started by: jerry on October 4, 2012, 04:21

Title: calculate the dipole moment
Post by: jerry on October 4, 2012, 04:21
Dear, recently, i have read an article which concentrates on the electronic structure of BN nanoribbons (built by substituting the carbon atoms of GNRs with boron and nitrogen atoms). In that paper they have calculated the transverse dipole moment of BNNR per unite cell, can you give me a script to do this using ATK?

Thanks a lot!
Title: Re: calculate the dipole moment
Post by: zh on October 4, 2012, 07:11
From the definition of dipole moment, you may do a bit coding to integrate the charge density  along a specific direction for the calculations of transverse dipole moment.
Title: Re: calculate the dipole moment
Post by: kstokbro on October 4, 2012, 07:39
For a script see:
http://www.quantumwise.com/documents/manuals/latest/ReferenceManual/index.html/ref.electrondifferencedensity.html
Title: Re: calculate the dipole moment
Post by: jerry on October 9, 2012, 03:05
Thank you very much for your kind reply!

Title: Re: calculate the dipole moment
Post by: jerry on October 13, 2012, 08:52
Dear,

I have refered to the reference manual. But here I want to calculate the transverse dipole moment as the one shown in Table 1 in J. Phys. Chem. C 2009, 113, 21213–21217. Can you give me the script on this which can be applied to calculate the BN nanoribbons?

Thank you very much!
Title: Re: calculate the dipole moment
Post by: Anders Blom on October 13, 2012, 21:39
If I understand the article correctly this is just the charge difference of the two edges divided by the width of the ribbon. Thus it's possible to compute from the Mulliken populations, although the precise definition of Dy (in the article) is not crystal clear.

You could also plot the electrostatic potential across the ribbon, either at different positions Z along the periodic cell, or averaged over Z. The slope of this is the electric field, which perhaps is not constant across the ribbon, but probably not rapidly varying either, at least not in the averaged case.
Title: Re: calculate the dipole moment
Post by: jerry on October 14, 2012, 03:26
Thank you very much for your kind reply :)