Setting up a DFT-D calculation in CASTEP

Hello everyone,

I am using CASTEP in Materials Studio version 5.5.3

to compute lattice cell volume with DFT-D by Grimme et al.

I'm getting results that are very off from what they are suppose to be from previous work that has been done using DFT-D.

Is there a special set-up for DFT-D calculation in CASTEP?

Thanks

Sammer