6 Common Problems and Solutions

6.1 DASP related

6.1.1 How to configure Pymatgen ?

• Pymatgen will be installed automatically when the user installs DASP. The pseudo-potential library in Pymatgen must be set to the 2003 version for VASP, otherwise, the results calculated by DASP program will be unreliable. However, the version of pseudopotential can be set arbitrarily in the DASP calculation. That is, potcar_path in dasp.in can correspond to any version of VASP pseudopotential.

6.1.2 How to place the sxdefectalign script

• Users can download sxdefectalign.bz2 by themselves from the website: https://sxrepo.mpie.de/projects/sphinx-add-ons/files<https://sxrepo.mpie.de/projects/sphinx-add-ons/files, and make the program sxdefectalign executable, namely chmod +x sxdefectalign , and add its path to the environment variables.

6.1.3 What is the role of file redo.in in PREPARE and DEC calculations?

• Users can modify the parameters of INCAR when they encounter errors in VASP, and then write the calculation directory to the file redo.in under the dec directory, namely dec/redo.in , and run the program again.

6.1.4 Hard disk is full and program cannot execute right.

• The wavefunction and charge density will be output by default in the DASP calculation (users can manually modify INCAR after PREPARE calculation and choose not to write), therefore, large disk space is required. If the storage space is used up, the task system may crash.

6.1.5 Can vasp_path_tsc and vasp_path_dec be set to the same?

• These two parameters can be set to the same. But we suggest vasp_path_dec uses the vasp_gam version because DASP does not support multiple k points to do defect calculations currently (namely band filling correction is not included).

6.1.6 Can spin polarization and spin-orbit coupling be considered?

• INCAR generated by DASP by default includes spin-polarization calculation, namely ISPIN=2 . If it is necessary to do the calculation including spin-orbit coupling, the path of VASP in dasp.in need to be changed to the vasp_ncl version, and modify the relevant parameters in INCAR after the PREPARE is completed.

6.2 Relevant issues in VASP calculation

6.2.1 VASP errors: issues related to SYMPREC

• Solution: Increase SYMPREC in INCAR and execute again. Users can manually set SYMPREC in INCAR after the PREPARE module is completed to avoid such errors.

6.2.2 The electronic step does not converge when using level=2 or 3 to do HSE self-consistent calculation.

• Solution: Change the algorithm, such as the ALGO tag in INCAR could select Damped or All (do not mixed with Normal). Or increase SIGMA , this parameter should be reset after converged, and calculated again with reading the converged wavefunction.

6.2.3 The electronic step does not converge when doing relaxation1, relaxation2, or static calculation in the first stage of TSC.

• Solution: In the first stage of TSC, the parameters in INCAR used for DASP calculation (PBE) are completely consistent with MP database, so they may not converge in a few cases, in which only need to change the algorithm and set ALGO=Fast or Normal in INCAR .

6.2.4 What to do when the calculation stops but does not converge during structure relaxation in the DEC module?

• Solution: Generally, copy CONTCAR to POSCAR and rerun the calculation.