QuantumATK Forum
QuantumATK => General Questions and Answers => Topic started by: njuxyh on January 22, 2019, 11:45
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Hi:
i want to get the correct band gap of graphene/mos2 heterostructure,
one method is to use MGGA, but as the manual said, the c-parameter should test manual because the supercell have big vacuum region, because there are no corresponding bulk graphene/mos2, so the c-parameter can not be determined by known value as the manual said,
so i am wondering how to test the MGGA-c-parameter.
and another question is is there any better to calculate the band gap of such two-dimensional heterostructure in ATK?
THANK YOU VERY MUCH
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The best alternatives are probably DFT-1/2 (same computational cost as GGA) and using PW with HSE06 (for reference calculations).
https://docs.quantumwise.com/tutorials/dft_half_pps/dft_half_pps.html
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i want to get the correct band gap of graphene/...
Pristine graphene has a zero gap, which is protected by the symmetry of the graphene lattice - two carbon sublattice are equivalent - and that does not depend on the DFT functional you are using.
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i want to get the correct band gap of graphene/...
Pristine graphene has a zero gap, which is protected by the symmetry of the graphene lattice - two carbon sublattice are equivalent - and that does not depend on the DFT functional you are using.
thank you, indeed prinstine graphene is gap-zero, but the MoS2/Graphene is non-zero small gap as many reference menthoned.
so i think it is depending on the the DFT functioanl useing maybe :)