[Pw_forum] how can I plot phonon dispersion and the a2F(omega) vs. omega function curve?

[Haruhiko Dekura]

Dear wangwei


> What is the meaning of the files named a2F.dos.1,..., a2Fdos.10?

alpha^2F: alpha^2 means electron-phonon coupling strength, and F means phonon density of states. 
Normally, we call this function as "Eliashberg function" in metallic system. In the formulation of a^2F, you see the delta functions and it's to be treated by Gaussian in espresso, and then we should have the smearing width of broadening. The number attached with a2F.dos.* correspond to the each width.  
a2Fdos file shows the a^2F as the function of  phonon frequency. 

> which file can be used to plot a2F(omega) vs. omega function curve and how to 
> plot it?

The best one is depending on the accuracy in your calculations.
I'would say, check the convergency of lambda with respect to the number of k-points in el-ph calculation, Gaussian smearing width, as well as typical checks before el-ph calculation (the convergency of phonon frequency and total electronic energy against Ecut and k-poins, smearing width...and so on.)

As for the plotting, you can select whatever you want to use, such as gnuplot. 



Best Regards. 
Haruhiko Dekura
       


On 2010/07/23, at 14:15, wangwei wrote:

> Dear sir,
> 
> I want to calulate phonon properties, including  phonon dispersion, dos, el-ph 
> coupling, and a2F(omega), 
> 
> now I have 4 questions (the version I used is 4.04):
> 
> 1. What is the meaning of the files named a2F.dos.1,..., a2Fdos.10?
> 
> 2. What is the meaning of the files named a2Fmatdyn51,...,matdyn60?
> 
> 3. how can I plot phonon dispersion using the file of case.freq?
> 
> 4. which file can be used to plot a2F(omega) vs. omega function curve and how to 
> plot it?
> 
> 
> Thanks for any reply!
> 
> Best wishes!
> 
> wangwei
> Huaibei Normal University
> 
> 
> 
> 
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