DFT+U: Difference between revisions
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go back to [[Main Page]], [[ | go back to [[Main Page]], [[Group Pages]],[[Núria López and Group]] | ||
To perform a ''DFT+U'' calculation using ''VASP'' you just have to add the following flags to your ''INCAR'' file: | |||
---- | |||
GGA = PW | PB | LM | 91 | PE | RP | PS | AM → The value of this flag depens on the ''DFT'' functional you want to use)[http://cms.mpi.univie.ac.at/vasp/vasp/GGA_tag.html] | GGA = PW | PB | LM | 91 | PE | RP | PS | AM → The value of this flag depens on the ''DFT'' functional you want to use)[http://cms.mpi.univie.ac.at/vasp/vasp/GGA_tag.html] | ||
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LASPH = .TRUE. → ''VASP'' recommends to add this flag to the ''INCAR'' file when using gradient corrected functionals. | LASPH = .TRUE. → ''VASP'' recommends to add this flag to the ''INCAR'' file when using gradient corrected functionals. | ||
LMAXMIX = 4 → DFT+U calculations may require LMAXMIX up to 4 for d-electrons (or 6 for f-elements) for faster convergence to the groundstate | |||
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'''IMPORTANT NOTES:''' | '''IMPORTANT NOTES:''' | ||
*In ''VASP'' there are several ''DFT + U'' approaches that can be used. You can specify the one you want by setting the corresponding value in the flag ''LDAUTYPE'' = "value". The default approach in ''VASP'' is the one introduced by Dudarev et al. (''LDAUTYPE ='' 2). For further details see ''VASP'' manual.[http://cms.mpi.univie.ac.at/vasp/vasp/On_site_Coulomb_interaction_L_S_DA_U.html] | *In ''VASP'' there are several ''DFT + U'' approaches that can be used. You can specify the one you want by setting the corresponding value in the flag ''LDAUTYPE'' = "value". The default approach in ''VASP'' is the one introduced by Dudarev et al. (''LDAUTYPE ='' 2).[http://prb.aps.org/abstract/PRB/v57/i3/p1505_1] For further details on this flag, see the online ''VASP'' manual.[http://cms.mpi.univie.ac.at/vasp/vasp/On_site_Coulomb_interaction_L_S_DA_U.html] | ||
*The values in ''LDAUL'', ''LDAUU'' and ''LDAUJ'' must be specified for all atomic species! | *The values in ''LDAUL'', ''LDAUU'' and ''LDAUJ'' must be specified for all atomic species! | ||
*It is not meaningful to compare the total energies resulting from calculations with different ''U'' and/or ''J'' (c.q. '' | *The default value in ''VASP'' for ''LDAUL'' is 2, so do not forget to specify your correct values for this flag in your ''INCAR'' file! | ||
*It is not meaningful to compare the total energies resulting from calculations with different ''U'' and/or ''J'' (c.q. ''U - J'' in case of Dudarev's approach). | |||
Latest revision as of 16:42, 5 November 2019
go back to Main Page, Group Pages,Núria López and Group
To perform a DFT+U calculation using VASP you just have to add the following flags to your INCAR file:
GGA = PW | PB | LM | 91 | PE | RP | PS | AM → The value of this flag depens on the DFT functional you want to use)[1]
LDAU = .TRUE.
LDAUL = "value" → It specifies the l-quantum number for which the on-site interaction is added (1 = p ; 2 = d ; 3 = f).
LDAUU = "value" → It specifies the effective on-site Coulomb interaction parameters (U).
LDAUJ = "value" → It specifies the effective on-site Exchange interaction parameters (J).
LASPH = .TRUE. → VASP recommends to add this flag to the INCAR file when using gradient corrected functionals.
LMAXMIX = 4 → DFT+U calculations may require LMAXMIX up to 4 for d-electrons (or 6 for f-elements) for faster convergence to the groundstate
IMPORTANT NOTES:
- In VASP there are several DFT + U approaches that can be used. You can specify the one you want by setting the corresponding value in the flag LDAUTYPE = "value". The default approach in VASP is the one introduced by Dudarev et al. (LDAUTYPE = 2).[2] For further details on this flag, see the online VASP manual.[3]
- The values in LDAUL, LDAUU and LDAUJ must be specified for all atomic species!
- The default value in VASP for LDAUL is 2, so do not forget to specify your correct values for this flag in your INCAR file!
- It is not meaningful to compare the total energies resulting from calculations with different U and/or J (c.q. U - J in case of Dudarev's approach).