DFT+U: Difference between revisions
Jump to navigation
Jump to search
No edit summary |
No edit summary |
||
| Line 24: | Line 24: | ||
*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). For further details see ''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'' | *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). | *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). | ||
*LASPH = .TRUE. | *LASPH = .TRUE. | ||
Revision as of 13:43, 25 October 2012
go back to Main Page, Núria López and Group, Computational Resources, Chemistry & More, Group Pages
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).
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).
- LASPH = .TRUE.