Best way to calculate magnetic susceptibility for Curie-Weiss temperature?

[Tharindu Fernando]

Hi,

I am still familiarizing myself with VAMPIRE, so I hope you will bear with me.

I would like to calculate the magnetic susceptibility for my sample with respect to temperature. My strategy so far was to use the monte-carlo integrator. However, this is proving to be very difficult for my thin film system (takes too long).

Are there other techniques I can use to calculate the susceptibility? My goal is to ultimately calculate the Curie-Weiss temperature to determine the magnetic ground state (whether my system is FM, AFM or paramagnetic).

In a video online, I saw a demonstration of the field-cooling program with llg-heun integrator. But I am not entirely sure of how to apply this in my case (I tried a time-series program with the llg-heun integrator at a fixed temperature, and a field-cool one with llg-heun). Nor am I sure of the reliability of this method compared to monte carlo.

So, do you have any advice on how I could calculate a reliable value of susceptibility for my instance, that is not monte carlo (if possible)? Any subtleties in parameters I should be aware of?

Thanks in advance!

Tharindu