# How can I get the plot of thermal conductivity from J0Jt.dat file?

Hello. all users.! Always thank you for your kindness!
I'm calculating the thermal conductivity of silicon by EMD green-kubo method using fix ave/corr command.
And here is the question.
In some papers such as The Journal of Chemical Physics 143, 154703 (2015), or Nano Lett. 2017, 17, 1269−1276,
they plot the thermal conductivity in terms of correlation time.

Can I get such plot of thermal conductivity from J0Jt.dat file? (I set the fix _ave/corr command to defalut value.)
Give me a hand!

I think that means you need multiple fix ave/correlate commands,

each with different params (correlation time) to produce different

stats, i.e. different Kappa values.

Steve

No, that is simply a plot of kappa as a function of the correlation time, ie. the evolution of a time-integral with increasing values of t.

Just perform step-wise numerical integration of the data contained in the J0Jt.dat file, multiply that by the appropriate scaling factor from the Green-Kubo formula, and you’re all set.

Arthur

First of all, thank you and Thank you for your kindness!!
It would be very helpful to me!

Sorry, but I want to ask two more question!

1.

Then, I would like to know if there is command in LAMMPS which performs to plot J0Jt .dat file in terms of the evolution of a time-integral with increasing values of time t ,
or if I have to plot by using another tools like Gnuplot, Origin, etc..??

2.
If I have to use multiple fix ave/correlate command, does it take more time to finish the calculation?

How can I solve this problem?
Sorry, and Thank you your interest!!
Thank you!

--------- 원본 메일 ---------보낸사람 : Arthur France-Lanord <[email protected]...>
받는사람 : Steve Plimpton <[email protected]...>

Replies below:

First of all, thank you and Thank you for your kindness!!
It would be very helpful to me!

Sorry, but I want to ask two more question!

1.

Then, I would like to know if there is command in LAMMPS which performs to plot J0Jt .dat file in terms of the evolution of a time-integral with increasing values of time t ,
or if I have to plot by using another tools like Gnuplot, Origin, etc..??

I may be wrong, but I don’t think that lammps can generate images of plots.

2.
If I have to use multiple fix ave/correlate command, does it take more time to finish the calculation?

It *will* be more compute intensive - but the additional overhead could be negligible. Just run some tests.

Arthur