Author Topic: DFT calcualtions using LCAO  (Read 1420 times)

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Offline AsifShah

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DFT calcualtions using LCAO
« on: April 10, 2023, 14:07 »
Dear admin,

Are DFT calculations using ATK LCAO calculator reliable for interfaces between 2D materials such as WS2 and Gold?
I have seen some discrepancies between interfacial distances calculated from VASP using plane-wave and ATK using LCAO.


Offline dprai

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Re: DFT calcualtions using LCAO
« Reply #1 on: April 11, 2023, 08:42 »
Did you take BSSE incorporating dispersion correction into consideration during the optimisation process?

Offline AsifShah

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Re: DFT calcualtions using LCAO
« Reply #2 on: April 11, 2023, 17:40 »
That is not possible as it gets very expensive computationally to optimize with BSSE. That is suitable for molecules on surface not interfaces with large number of atoms, I guess.

Offline Anders Blom

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Re: DFT calcualtions using LCAO
« Reply #3 on: April 25, 2023, 22:32 »
Which dispersion correction are you using? This is probably more relevant than BSSE in this case, which is more applicable when computing the formation energy.

Offline AsifShah

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Re: DFT calcualtions using LCAO
« Reply #4 on: May 1, 2023, 20:04 »
DFTD3

Offline Anders Blom

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Re: DFT calcualtions using LCAO
« Reply #5 on: May 2, 2023, 07:17 »
Ok. Some small difference in results can always occur between different basis sets and pseudopotentials. It should make the final conclusions of the calculations wrong or invalid, as long they are internally consistent. You could test by running with the QuantumATK planewave basis set, to at least have the same pseudopotential for LCAO and PW.