The search for an EFG equation of state in ThM3 compounds (with M=Sn, In, Si, Ge, Ga, Rh, Pb, Tl)

I have investigated the behavior of the electric field gradient (EFG) at M site in ThM3 compounds (with M=Sn, In, Si, Ge, Ga, Rh, Pb, Tl) under pressure. I have found that the magnitude of EFG increases with pressure in all compounds. Furthermore I have shown that in ThM3 (with M=In, Ga, Pb, Tl), this increase follows a common trend. Thereby I have reached an equation of state for the EFG in this group.