[Wien] construction supercell

[Stefaan Cottenier]

> You are saying that the lattice constant will be changed with 'x'
parameter
> and that there are simple empirical laws giving a linear relation. Would
you
> give me more information about these laws for example where can i find
them.
> Also we have some experimental lattice constants for some concentrations.
Is
> it possible to use this experimental ones in wien2k calculations and then
> try to find lowest enegy. Thanks in advance. Thank you Cottenier also.

What Kevin means, is called 'Vegard's law': the lattice constant of an alloy
between two isostructural materials changes linearly from 0% to 100%. You
could calculate the lattice constant for bcc-Fe and for bcc-Mn, and use the
linear interpolation for the (bcc) alloys (assuming you want to study bcc
alloys). Alternatively, you could also do volume optimization for a few
alloys, but this will probably need very large cells and for sure internal
optimization as well in order to find Vegard's law.

You can use the experimental values as well, but I would think it is a
little bit cleaner if you don't mix too much experimental and theoretical
information.

Stefaan