Logo Welcome to dfttk_example’s documentation!

Example

To get the example, run

git clone https://github.com/yiwang62/dfttk_example #if you have not download the example
cd dfttk_example

The example is designed to have the user to test the DFTTK package using Al. The input settings for the Al example are contained in the Al/ folder by two files

  • POSCAR - the regular VASP POSSCAR file

  • SETTINGS.yaml - the setting file for quasiharmonic phonon calculation

The following gives the steps to run the Al example

cd Al
dfttk run -wf robust -f POSCAR -l -m 1

This will submit the batch DFT job to the system. One can check the progress of the DFT calculations by lpad get_wflows. Only when all the values for the ‘states_list’ fields are shown as ‘C’ implies the DFT job done. Then One can go to next step by run

cd dfttk_example #go back the dfttk example folder
dfttk thfind -get -plot DFTTK -expt ExptData.json

The file ExptData.json under the dfttk_example folder contains some experimental thermodynamic data for a collection of materials to verify the DFTTK calculations. The above will produce more thatn 20 figures stored in the folder Al_Fm-3m_225PBE/figures and they can be viewed t by clicking them in Windows/IOS or using the linux command display to show the figure. For example for linux

display Al_Fm-3m_225PBE/figures/LTC.png #to see the linear thermal expansion coefficient
_images/Al-LTC.png
display Al_Fm-3m_225PBE/figures/Heat_capacities.png #to see the heat capaticity, and so on
_images/Al-Heat_capacities.png

The Al_Fm-3m_225PBE/ folder contains all calculated thermodynamic properties after post-processing the data stored in the MongoDB database for a finished DFT calculations, in particular

  • figures/ - plots in png format for most of the thermodynamic properities

  • readme - extensive summary of the calculated results in json format

  • fvib_ele - tablated data containing the calculated thermodynamic properties

  • fvib_eij - tablated data containing the calculated thermal expansion coefficient tensor

  • record.json - SGTE fitting record for heat capacity, Gibbs energy, enthalpy, and entropy at given temperature range

Indices and tables