## Exchange coupling constant in micromagnetic simulation

Hi, all.

I'm wondering if anyone's done some simulation of magnetic material with LLG equation. The question is where can I find the value of exchange constant for a material.

In LLG equation, the exchange constant is in the unit of "J/m", and the typical value is 10^-11 J/m, for some magnetic metal as far as I know. But I can't find a handbook or any online material summarizing this parameter for different materials. It seems complicated to derive based on the structure. Does anyone know where to look for such values?