# [Wien] Virtual-crystal

Jihoon Park jpark61 at crimson.ua.edu
Thu Aug 23 17:31:01 CEST 2012

```Dear Users,

I am trying to perform a calculation using "virtual-crystal" method.
I have found the way to do this and it is as below.

- run through inil_lapw using default atomic numbers
- edit nuclear charges in case.struct
- edit corresponding occupancies in case.inst
- edit the total number of electrons in case.in2
- run SCF circle

But I do not understand a few things.

First, I do not know how I should change the occupation number. I have looked up the manual, but still confused.
Just say that I want to do x = 0.5 for example, then what should I edit? There are numbers like "1.0, 2.0, 3.0 and so on..."

Second, if I want to add one more electron in the unit cell (two f.u., therefore x = 0.5), should I just do the # of electron + one in case.in2?
For example, if the current # of electrons is 25, should I put the # of electrons as 26?

All my best,
Jihoon Park

2012-08-21 오후 11:09, Jihoon Park 쓴 글:
> Dear Users,
>
>
> I am trying to perform a calculation using "virtual-crystal" method.
> I have found the way to do this and it is as below.
>
> - run through inil_lapw using default atomic numbers
> - edit nuclear charges in case.struct
> - edit corresponding occupancies in case.inst
> - edit the total number of electrons in case.in2
> - run SCF circle
>
>
> But I do not understand a few things.
>
> First, I do not know how I should change the occupation number. I have looked up the manual, but still confused.
> Just say that I want to do x = 0.5 for example, then what should I edit? There are numbers like "1.0, 2.0, 3.0 and so on..."
>
> Second, if I want to add one more electron in the unit cell (two f.u., therefore x = 0.5), should I just do the # of electron + one in case.in2?
> For example, if the current # of electrons is 25, should I put the # of electrons as 26?
>
>
> All my best,
> Jihoon Park
>

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