Page 1 of 1

Dipole Moment in non-cubic supercells

Posted: Mon May 26, 2025 6:34 am
by parvathy_p

I was working on the adsorption of a charged monomer (stabilized using LDIPOL (dipole moment) and NELECT tags) on an MXene slab. The MXene has a hexagonal unit cell and when I created a monolayer of the substance and tried doing adsorption, it didn't work because the calculations can only be done on cubic systems. which means LDIPOL = .TRUE. wouldn't work.
I read somewhere that the newest version of VASP supports this calculation in any orthogonal cell. So, I tried converting the hexagonal system into orthorhombic using atomsk and then ran using VASP 6.5.1 but the same error came saying that this calculation is only possible for cubic structures.
Does that mean we cannot do charged calculations in non-cubic cells at all?


Re: Dipole Moment in non-cubic supercells

Posted: Fri Jun 06, 2025 7:18 am
by henrique_miranda

This is true for the usual LDIPOL=.TRUE. in the case of charged systems, but as mentioned in this post:
https://www.vasp.at/forum/viewtopic.php?p=31476#p31276
you might be able to get what you need using the KERNEL_TRUNCATION approach.


Re: Dipole Moment in non-cubic supercells

Posted: Thu Jun 26, 2025 3:53 am
by parvathy_p

My calculations are done using DFT D2 since they involve adsorption studies. From what i gather, KERNEL_TRUNCATION is used with hybrid functionals, right? But thank you very much.


Re: Dipole Moment in non-cubic supercells

Posted: Fri Jun 27, 2025 11:11 am
by henrique_miranda

No, KERNEL_TRUNCATION currently only applies to DFT: the hartree and ionic potential.
The extension to Hybrid functionals (fock) is in our plans but currently not implemented.