RE: [SIESTA-L] How does siesta calculate bands in a gamma-point-only scf calculation?

2022-02-01 Por tôpico Chong Wang 
Thanks. That’s exactly what I needed.

Chong

From: Nick Papior<mailto:nickpap...@gmail.com>
Sent: Saturday, January 29, 2022 1:04 PM
To: siesta-l<mailto:siesta-l@uam.es>
Subject: Re: [SIESTA-L] How does siesta calculate bands in a gamma-point-only 
scf calculation?

Hi,

Simply add this to your fdf file:

ForceAuxCell true


Den fre. 28. jan. 2022 kl. 22.01 skrev Chong Wang 
mailto:ch-w...@outlook.com>>:
Dear siesta developers,

I am trying to read HSX file and calculate corresponding band structure myself 
(because I need wave function information). The HSX file is generated with a 
gamma-point-only scf calculation, and thus it is necessary to do some 
modification to the `xij` variable.

For example, suppose I have a ten-atom chain:
1-2-3-4-5-6-7-8-9-10

A gamma point calculation will introduce hopping between atom 1 and atom 10 
(<1|H|10>) due to periodic boundary condition. To calculate band structure, it 
is necessary to realize the hopping is across the cell boundaries. Currently, 
`xij` is the vector pointing from 1 to 10 in the home unit cell:
1>10.
Some modification is needed such that it points to the left side of the unit 
cell:
10<-1-2-3-4-5-6-7-8-9-10.

I can do this modification myself, but I guess there is already a subroutine in 
siesta that does this trick. Where is it?

Best
Chong Wang


--
SIESTA is supported by the Spanish Research Agency (AEI) and by the European 
H2020 MaX Centre of Excellence (http://www.max-centre.eu/)


--
Kind regards Nick


-- 
SIESTA is supported by the Spanish Research Agency (AEI) and by the European 
H2020 MaX Centre of Excellence (http://www.max-centre.eu/)

Re: [SIESTA-L] How does siesta calculate bands in a gamma-point-only scf calculation?

2022-01-29 Por tôpico Nick Papior 
Hi,

Simply add this to your fdf file:

ForceAuxCell true


Den fre. 28. jan. 2022 kl. 22.01 skrev Chong Wang :

> Dear siesta developers,
>
>
>
> I am trying to read HSX file and calculate corresponding band structure
> myself (because I need wave function information). The HSX file is
> generated with a gamma-point-only scf calculation, and thus it is necessary
> to do some modification to the `xij` variable.
>
>
>
> For example, suppose I have a ten-atom chain:
>
> 1-2-3-4-5-6-7-8-9-10
>
>
>
> A gamma point calculation will introduce hopping between atom 1 and atom
> 10 (<1|H|10>) due to periodic boundary condition. To calculate band
> structure, it is necessary to realize the hopping is across the cell
> boundaries. Currently, `xij` is the vector pointing from 1 to 10 in the
> home unit cell:
>
> 1>10.
>
> Some modification is needed such that it points to the left side of the
> unit cell:
>
> 10<-1-2-3-4-5-6-7-8-9-10.
>
>
>
> I can do this modification myself, but I guess there is already a
> subroutine in siesta that does this trick. Where is it?
>
>
>
> Best
>
> Chong Wang
>
>
>
> --
> SIESTA is supported by the Spanish Research Agency (AEI) and by the
> European H2020 MaX Centre of Excellence (http://www.max-centre.eu/)
>


-- 
Kind regards Nick

-- 
SIESTA is supported by the Spanish Research Agency (AEI) and by the European 
H2020 MaX Centre of Excellence (http://www.max-centre.eu/)