fix a number of vacancy site

Alloy Theoretic Automated Toolkit (ATAT)
1

Hi,

I’ve been trying to fix the composition of a vacancy during cluster expansion.
For example, when the system has 36 atoms consisting of Carbon, is there a way to consider the case only when a number of vacancy is 4?

I know that I can assign the position of vacancy, but I’d like to have 4-vacancy site which is randomly assigned out of 36 atoms while fixing the number of system is 36.

Alternatively, it’d be also great if it is possible to increase a number of vacancy as a step of 2, 4, 6, etc.

Thank you in advance.

2

Do mmaps -h and read about the crange.in file.
In maps, look at the -c0 and -c1 options.
You may also want to recompile with the -DDEGE_GS flag.
Before you do this , however, consider if it makes sense: if the system can exchange C with the environment , a composition constraint may mask what is the true equilibrium .