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tutorials:bse1 [2016/04/24 15:09] – ↷ Page moved from howto:bse1 to tutorials:bse1 Yann Pouillontutorials:bse1 [2016/04/24 15:09] (current) – ↷ Links adapted because of a move operation Yann Pouillon
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-**[[|2.]] Computing the absorption spectrum within the Tamm-Dancoff approximation. **+**[[howto:start|2.]] Computing the absorption spectrum within the Tamm-Dancoff approximation. **
  
 This section is intended to show how to perform a standard excitonic calculation within the Tamm-Dancoff approximation (TDA) using the Haydock iterative technique. The input file is ~abinit/tests/tutorial/Input/tbs_2.in. This section is intended to show how to perform a standard excitonic calculation within the Tamm-Dancoff approximation (TDA) using the Haydock iterative technique. The input file is ~abinit/tests/tutorial/Input/tbs_2.in.
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-**[[|2.d]] Preliminary discussion about convergence studies **+**[[howto:start|2.d]] Preliminary discussion about convergence studies **
  
 Converging the excitonic spectrum requires a careful analysis of many different parameters: Converging the excitonic spectrum requires a careful analysis of many different parameters:
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-**[[|3.]] Convergence with respect to the number of bands in the transition space ** In this section we take advantage of the multi-dataset capabilities of ABINIT to perform calculations with different values for [[../input_variables/vargw.html#bs_loband|bs_loband]] and [[../input_variables/varbas.html#nband|nband]]+**[[howto:start|3.]] Convergence with respect to the number of bands in the transition space ** In this section we take advantage of the multi-dataset capabilities of ABINIT to perform calculations with different values for [[../input_variables/vargw.html#bs_loband|bs_loband]] and [[../input_variables/varbas.html#nband|nband]]
  
 Before running the test take some time to read the input file ~abinit/tests/tutorial/Input/tbs_3.in. Before running the test take some time to read the input file ~abinit/tests/tutorial/Input/tbs_3.in.
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-**[[|5.]] Convergence with respect to the number of planewaves in the screening **+**[[howto:start|5.]] Convergence with respect to the number of planewaves in the screening **
  
 First of all, before running the calculation, take some time to understand what is done in ~abinit/tests/tutorial/Input/tbs_4.in. First of all, before running the calculation, take some time to understand what is done in ~abinit/tests/tutorial/Input/tbs_4.in.
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-**[[|6.]] Convergence with respect to the number of k-points ** The last parameter that should be checked for convergence is the number of k-points. This convergence study represents the most tedious and difficult part since it requires the generation of new KSS files and of the new SCR file for each k-mesh (the list of k-points for the wavefunctions and the set of q-points in the screening must be consistent with each other).+**[[howto:start|6.]] Convergence with respect to the number of k-points ** The last parameter that should be checked for convergence is the number of k-points. This convergence study represents the most tedious and difficult part since it requires the generation of new KSS files and of the new SCR file for each k-mesh (the list of k-points for the wavefunctions and the set of q-points in the screening must be consistent with each other).
  
 The file ~abinit/tests/tutorial/Input/tbs_5.in gathers the different steps of a standard BS calculation (generation of two KSS file, screening calculation, BS run) into a single input. The calculation is done with the converged parameters found in the previous studies, only [[../input_variables/varbas.html#ngkpt|ngkpt]] has been intentionally left undefined. The file ~abinit/tests/tutorial/Input/tbs_5.in gathers the different steps of a standard BS calculation (generation of two KSS file, screening calculation, BS run) into a single input. The calculation is done with the converged parameters found in the previous studies, only [[../input_variables/varbas.html#ngkpt|ngkpt]] has been intentionally left undefined.
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-**[[|6.]] Additional exercises (optional) **+**[[howto:start|6.]] Additional exercises (optional) **
  
   * Use [[../input_variables/vargw.html#bs_coupling|bs_coupling]]=1 to perform an excitonic calculation for silicon including the coupling term. Compare the imaginary part of the macroscopic dielectric function obtained with and without coupling. Do you find significant differences? (Caveat: calculations with coupling cannot use the Haydock method and are much more CPU demanding. You might have to decrease some input parameters to have results in reasonable time.)   * Use [[../input_variables/vargw.html#bs_coupling|bs_coupling]]=1 to perform an excitonic calculation for silicon including the coupling term. Compare the imaginary part of the macroscopic dielectric function obtained with and without coupling. Do you find significant differences? (Caveat: calculations with coupling cannot use the Haydock method and are much more CPU demanding. You might have to decrease some input parameters to have results in reasonable time.)
tutorials/bse1.1461503380.txt.gz · Last modified: 2016/04/24 15:09 by Yann Pouillon