Dear all,
In the case of MBJ calculation, let's say I have specified in my input file the following two lines.
GGA = PE
METAGGA= MBJ
Does this mean the exchange-correlation energy functional is taken from PBE?
With regards,
Bikash.
Question regarding MBJ functional?
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bikash.patra
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fabien_tran1
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Re: Question regarding MBJ functional?
Hi,
In general, it does not make sense to specify both GGA and METAGGA tags simultaneously in INCAR, because METAGGA will be used and GGA ignored. So, Either GGA or METAGGA should be used. Actually, since vasp.6.4.0 the simultaneous use of GGA and METAGGA leads to a stop of the calculation.
When METAGGA=MBJ is chosen, the xc energy functional is LDA and this can not be changed because this is hard coded. The LDA call is "CALL CORPBE ..." (only the LDA component of PBE is considered) in the block "ELSEIF (ID_METAGGA==30)" in metagga.F.
In general, it does not make sense to specify both GGA and METAGGA tags simultaneously in INCAR, because METAGGA will be used and GGA ignored. So, Either GGA or METAGGA should be used. Actually, since vasp.6.4.0 the simultaneous use of GGA and METAGGA leads to a stop of the calculation.
When METAGGA=MBJ is chosen, the xc energy functional is LDA and this can not be changed because this is hard coded. The LDA call is "CALL CORPBE ..." (only the LDA component of PBE is considered) in the block "ELSEIF (ID_METAGGA==30)" in metagga.F.