How to saturate slab bonds with partial charge H in Dmol3?

Hello,

I am attempting to create a slab of the (001) GaSb surface for an adsorption study. To properly simulate the bonding of the Ga atoms in the bottom of the slab requires capping them with partially charged (1.25e) Hydrogen (see yellow atoms in the image below) I have not been able to find any documentation on specifying partial charge H atoms within DMol, but I did find a paper which does just that: Carter et al. Phys. Rev. B. 77, 115349, 2008. Is this still possible in DMol? If so, how would I go about it?

Thank you.

slab_frac_H.bmp