Hi @sherif_Yehia,
This value reported is the ‘total magnetization’ of the crystallographic cell as reported by VASP. In the case of GdScSi, it looks like there are two formula units per unit cell, so it would be 7.9 µB per formula unit (this is about right, because the Gd atom is usually of order ~10 µB or slightly smaller, and the Sc, Si atoms are likely non-magnetic, but I would have to check).
We are expanding the information we report for magnetic materials, so please let us know if there is any additional information you would find useful.
Best,
Matt