:math:`\alpha`-Ce with spin-orbit interaction --------------------------------------------- In this example, you will learn how to perform a DFT+G calculation using Wien2k plus CyGutz packages, including some typical post-analyses. 1) Finish a self-consistent lapw + spin-orbit calculation for :math:`\alpha`-Ce using WIEN2k. Please follow the following steps: (a) create a directory with name 'Ce', change to that directory, and download the structure file :download:`Ce.struct <_files/Ce.struct>`. (b) type the following command to initialize the wien2k job:: $ ${WIENROOT}/init_lapw use the answers below for the questions: * Enter reduction in %: enter (choose default) * Use old or new scheme (o/N): enter * Do you want to accept these radii... (a/d/r): enter * nn (14:13:54) specify nn-bondlength factor: enter * continue with sgroup or edit the Ce.struct file (c/e): enter * continue with symmetry (old case.struct) ...: enter * continue with lstart or edit the Ce.struct_st file (c/e/x): enter * Eventually specify switches for instgen_lapw: enter * lstart ... SELECT XCPOT: 5 * SELECT ENERGY to separate core and valence states: -6.0 * continue with kgen or edit the Ce.inst file ... (c/e): enter * in 2nd line of Ce.in1_st file, change 7.00 (R-MT*K-MAX) to 9.00 * kgen NUMBER OF K-POINTS IN WHOLE CELL: 5000 * continue with dstart or execute kgen again or exit (c/e/x): enter * do you want to perform a spinpolarized calculation ? (n/y): n (c) type the following command to run lapw job:: $ ${WIENROOT}/run_lapw check the last line of `Ce.scf` file, which should give a LDA total energy close to -17717.65311 Ryd. (d) type the following command to add spin-orbit interaction:: $ ${WIENROOT}/initso_lapw use the answers below for the questions: * Please select the direction of the moment ( h k l ): enter * for which you would NOT like to add SO interaction: enter * Please enter EMAX(default 5.0 Ryd): 7.5 * Add RLO for NONE, ALL, CHOOSE elements? (N/a/c) : enter * in Ce.inso file, change the 3rd line by replacing 1.5 with 4.5 (Emax) * Do you have a spinpolarized case ...: enter (e) type the following command to run lda calculation with spin-orbit:: $ ${WIENROOT}/run_lapw -so check the last line of `Ce.scf` file, which should give a LDA+so total energy close to -17717.67370 Ryd. Use the following command to save the result:: $ ${WIENROOT}/save_lapw -d lapwso 2) We are ready to initialize the DFT+G calculation. Type:: $ ${WIEN_GUTZ_ROOT2}/init_ga.py Use the following answers or the questions: * Do you want to BREAK SPIN-SYMMETRY: n * Do you want to COMPLETELY break orbital-symmetry: n * Do you want to take into account the SPIN-ORBIT interaction: y * Do you want to take into account the CRYSTAL FIELD effect: n * Please select the method to parametrize Coulomb U-matrix: 1 * Please select method for U-interaction double counting: 12 * Symmetrically-equivalent atom indices ...: y * atom 0 Ce: * Is this atom correlated: y * Enter correlated shells: f * Please provide interaction parameters U,J ... (eV): 6.0 0.7 * Please provide initial guess ... of localized f-electrons: 1.0 * Please select the method to solve G-RISB equations: 0 * Please select the method to solve embedding Hamiltonian: -1 Thus it finishes the setup of all the necessary files for CyGutz. The main output file of the initialization is stored in `init_ga.slog` file. The user-provided entries is stored in HDF5 file `ginit.h5` for the convenience of re-initialization. 3) To run the DFT+G calculation, type:: $ ${WIEN_GUTZ_ROOT2}/run_ga.py Check the last line of `Ce.scf` file, which should give a LDA+so+G total energy close to -17717.60065 Ryd. The main output message of CyGutz calculation is printed in `GUTZ.LOG` file in text format. The DFT+G calculation can be saved using the following commands:: $ ${WIEN_GUTZ_ROOT2}/save_ldag -d lapwg 4) Let us learn how to plot the density of states of Ce after the self-consistent DFT+G calculation. To plot density of states with Ce-4f character, type:: $ ${WIEN_GUTZ_ROOT2}/plot_dos_tf.py -h # help info $ ${WIEN_GUTZ_ROOT2}/plot_dos_tf.py -el -3.0 -eh 5.0 you will get dos like .. image:: _images/ce_dos.png :alt: alternate text :scale: 100 % :align: center The above scirpt calls a predefined functions, which serves a s a template to be adapted by users for specific purposes. .. autofunction:: pyglib.estructure.dos.driver_plot_dos 5) Another important analysis is the eigen-values of the local reduced many-body density matrix using the exponential form :math:`\rho=e^{-F}`, as shown in the figure below: .. image:: _images/ce_hist_jj.png :alt: alternate text :scale: 100 % :align: center Follow the steps below to get the analysis done for the first impurity. (a) type:: $ ${WIEN_GUTZ_ROOT2}/exe_spci_j2_mott_analysis 1 (b) Use :download:`plot_hist_ce.py <_files/plot_hist_ce.py>` to plot by typing:: $ python ./plot_hist_ce.py The above scirpt calls two predefined functions, which serves a s a template to be adapted by users for specific purposes. .. autofunction:: pyglib.mbody.multiplets_analysis_soc.calc_save_atomic_states .. autofunction:: pyglib.mbody.multiplets_analysis_soc.plot_atomic_states 6) To calculate the bands structure along selected k-path, follow the steps below: (a) Prepare the Ce.klist_band file for the high-symmetry k-path of the primitive Brillouin Zone. The SRC_templates directory of Wien2k has some examples. For instance, we can use `fcc.klist` file. Type the command to get the file:: $ cp ${WIENROOT}/SRC_templates/fcc.klist Ce.klist_band (b) Type the following command to calculate the band structure:: $ ${WIEN_GUTZ_ROOT2}/run_ga.py -band (c) To plot the band structure with Ce-3f character, type:: $ ${WIEN_GUTZ_ROOT2}/plot_band_tf.py -h # help info $ ${WIEN_GUTZ_ROOT2}/plot_band_tf.py You will see the band structure like the following .. image:: _images/ce_bands.png :alt: alternate text :scale: 100 % :align: center The above scirpt calls a predefined function, which serves a s a template to be adapted by users for specific purposes. .. autofunction:: pyglib.estructure.bandstruct.driver_plot_bands