Zeolite rigid body

ahhill

I am wanting to set up a rigid body for a SiO4 tetrahedron, i.e constrain the Si-O ad O-O distances and angles to all be the same. I also want to constrain the Si-O-Si lengths and angles to be the same between tetrahedra.

I think i should be doing something like the following (is it even correct?). How can I force the tetrahedra to corner share? Has anyone got a rigid body inp file for a zeolite type refinement?

prm r 1.61
prm ang 109.5
rigid
load z_matrix (
Si1
O1 Si1 =r;
O2 Si1 =r; O1 =ang;
O3 Si1 =r; O1 =ang; O2 =ang;
O4 Si1 =r; O3 =ang; O2 =ang;
}

Any tips out there?

Thanks

mfisch

Hi Adrian

Wouldn't you need to know how many of those rigid bodies you need? Then occ_merge, ass soon as ligand O's are closer together than a minimum distance, which will build up a SiO4 chain?

I am actually a bit afraid that you shouldn't setup rigid bodies but the whole framework and then constrain all angles and distances...?

Regards
Martin

ahhill

Cheers Martin.

Yes I am thinking along the restriant procedure as well.

Adrian