Author Topic: Is it possible to extract the fitted MTP parameter set?  (Read 1242 times)

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Offline sukhito teh

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Dear developers and users,
Happy new year to all!
I am doing some calculation with the MomentTensorPotentialTraining module and couldn't find a way to extract the fitted parameters. The reason why I am interested in these fitted parameters is to calculate the local potential/forces as mentioned in this paper (https://doi.org/10.1103/PhysRevB.105.115202). Can someone clarify if the extraction is possible within quantumatk?

best regards
sukhito teh

« Last Edit: January 6, 2023, 12:16 by sukhito teh »

Offline Anders Blom

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Re: Is it possible to extract the fitted MTP parameter set?
« Reply #1 on: January 18, 2023, 00:49 »
You should definitely be able to perform the same kind of calculations as in the paper you mention with QuantumATK! But there is no need at all to extract the MTP parameters for that, nor is it particularly useful even if you could, as they are just a huge number of numerical coefficients without physical meaning. By setting up the right training protocol and fitting the MTP, you will obtain a forcefield model that can be directly used to compute the phonon frequencies, eigenmodes etc, and perform MD calculations, all within QuantumATK itself.

Offline sukhito teh

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Re: Is it possible to extract the fitted MTP parameter set?
« Reply #2 on: February 13, 2023, 05:26 »
Thank you for your reply. Please correct me if am wrong, the mentioned paper used Green-Kubo approach to calculate, and the method required the kinetic energy, potential energy and potential derivative of individual atoms, we can use funtcion ConfigurationVelocities to calculate kinetic energy part and function Forces to calculate the potential derivative. However, I can't find a way to extract potential or total energy of individual atom.


 
« Last Edit: February 17, 2023, 14:59 by sukhito teh »

Offline sukhito teh

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Re: Is it possible to extract the fitted MTP parameter set?
« Reply #3 on: February 21, 2023, 10:25 »
Thank you for your reply. Please correct me if am wrong, the mentioned paper used Green-Kubo approach to calculate, and the method required the kinetic energy, potential energy and potential derivative of individual atoms, we can use funtcion ConfigurationVelocities to calculate kinetic energy part and function Forces to calculate the potential derivative. However, I can't find a way to extract potential or total energy of individual atom.


 
Nevermind, built in features of quantumatk can use this method (https://aip.scitation.org/doi/10.1063/5.0089247) to calculate thermal conductivity, the results are pretty good.