DFT+U: Difference between revisions
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LDAUJ = "value" → It specifies the effective on-site Exchange interaction parameters (''J''). | 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. | |||
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*It is not meaningful to compare the total energies resulting from calculations with different ''U'' and/or ''J'' (c.q. ''Ueff = U - J'' in case of Dudarev's approach). | *It is not meaningful to compare the total energies resulting from calculations with different ''U'' and/or ''J'' (c.q. ''Ueff = U - J'' in case of Dudarev's approach). | ||
Revision as of 13:45, 25 October 2012
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UNDER CONSTRUCTION...
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.
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.[2]
- 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. Ueff = U - J in case of Dudarev's approach).