[QE-users] band structure with hybrid functional HSE

[Lorenzo Paulatto]

> Is there a workaround?

Hello,
The problem is quite fundamental, because in order to get the Fock 
operator at a certain k-point you need the wavefunctions on a grid that 
is commensurate with it, this can only be done self-consistently.

However, there are a few things you can do.

1. I think you can add k-points to the scf calculation with weight zero, 
this is boring (you'll have to specify he grid and the path by hand) and 
very computationally expensive.

2. you can interpolate the Fock operator, this should be possible if it 
is expressed om a basis of localized wavrfunctions. There is some 
development in this direction, but I don't know if it has been 
implemented already by someone.

3. You could interpolate the wavefunctions, from Wannier functions. This 
is probably impossible in practice.

4. You can interpolate the Hamiltonian, passing through a Wannier basis 
representation. This is possible, I have done it, and I've put an 
example in the git developement branch 
(PP/examples/W90_open_grid_example/). But you need to know, or learn, 
how to use Wannier90 (which is a useful skill regardless), and to use 
the developement version of qe.

kind regards

> 
> 
> Best,
> Stefan Seidl
> 
> 
> _______________________________________________
> users mailing list
> users at lists.quantum-espresso.org
> https://lists.quantum-espresso.org/mailman/listinfo/users
> 

-- 
Lorenzo Paulatto - Paris