Beginner tutorial for Density Functional Theory(DFT) calculation using Quantum Espresso(QE)[1,2]
- A working version of QE needs to be installed/compiled and the executables needs to be located in the PATH environmental variable or specified manually in the variable BIN_DIR.
- A working version of gnuplot (>=5.0) (The exercises script will generate gnuplot file to plot the results. Other programs can also be used)
- A working version of XCrySDen, a program that can visualize input and output files of QE.
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QE can be installed from repository for Debian based linux distros (e.g.: Ubuntu) by running the command
sudo apt-get install quantum-espresso
PS: The max version of QE that can be installed this way is ... maybe 6.0 now
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QE can be compiled from source:
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Download the desired release version from the GitHub page "https://github.com/QEF/q-e/releases".
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Unzip/tar the downloaded package and go inside the folder.
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From terminal run the commands
./configure --prefix=path for installation make all make install
NOTES: options for the configuration / use of external libraries for optimized executables is beyond the purpose of this tutorial.
- Construct an input file for a choosen system and visualize it using xcrysden
- Run a simple self-consistent calculation using pw.x
- Estimate the kinetic cutoff convergency
- Determine the theoretical lattice parameter
- Calculate a charge density and visualize it using XCrySDen
- Generate a high-symmetry k-path using xcrysden and calculate a band structure
- Calculate the density of states(DOS) and optical properties(independent particle approximation) and show the convergence over the number of k_points and empty bands used
- How to use a supercell in order to run calculation for material that are not periodic in all directions.
- Run calculation for a metallic/semimetallic system
- Run a relax calculation and visualize the output using xcrysden
- Run a calculaiton for a molecule (0D system)
- Calculate the binding energy of a molecule
- Visualize the HOMO and LUMO of a molecule (charge density for specific k-point and band)
- Use a Lennard-Jones like potential to fit the data 'E_tot' vs 'bond lenght'
- Docs: Contain additional tutorials in pdf format
- Codes: Contain user-made code to analyze some of the data produced by QE
- boad.c (by Davide Grassano aka Crivella): Apply a gaussian broadening(to the y_n data) to a multicolumn file where the 1st column represents the x data and the 2nd,3rd,... columns represent the y_1, y_2, ... data.
- plot_pwbands.f90 (by ...) : ...
- Pseudo: Contain the pseudopotential required to perform the exercises
- P. Giannozzi, S. Baroni, N. Bonini, M. Calandra, R. Car, C. Cavazzoni, D. Ceresoli, G. L. Chiarotti, M. Cococcioni, I. Dabo, et al., Journal of physics: Condensed matter 21, 395502 (2009).
- P. Giannozzi, O. Andreussi, T. Brumme, O. Bunau, M. B. Nardelli, M. Calandra, R. Car, C. Cavazzoni, D. Ceresoli, M. Cococcioni, et al., Journal of Physics: Condensed Matter 29, 465901 (2017).