Editing DFT+U

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To perform a ''DFT+U'' calculation using ''VASP'' you just have to add the following flags to your ''INCAR'' file:


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GGA   = PW | PB | LM | 91 | PE | RP | PS | AM  &rarr; 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]

LDAU  = .TRUE.

LDAUL = "value"  &rarr; It specifies the ''l''-quantum number for which the on-site interaction is added (1 = p ; 2 = d ; 3 = f). 

LDAUU = "value" &rarr; It specifies the effective on-site Coulomb interaction parameters (''U''). 

LDAUJ = "value" &rarr; It specifies the effective on-site Exchange interaction parameters (''J''). 

LASPH = .TRUE. &rarr; ''VASP'' recommends to add this flag to the ''INCAR'' file when using gradient corrected functionals.

LMAXMIX = 4  &rarr; 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:'''

*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 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).