Hi, I need to make a 3D model of Barium Hydroxide but do not know the angle measurements to put the sticks at connecting the barium to the oxygen. (It is a ball and stick model) I just need to know the angle degrees between barium and the oxygen and the oxygen to hydrogen. Thank-you

From here : Barium hydroxide - Wikipedia, the free encyclopedia (http://en.wikipedia.org/wiki/Barium_hydroxide)

We know that the crystal is of octahedral structure.

What is that? Well, it's similar to: Octahedral molecular geometry - Wikipedia, the free encyclopedia (http://en.wikipedia.org/wiki/Octahedral_molecular_geometry)

Except that barium is an ionic compound and the page is about octahedral molecules.

So, they are just at 90 degrees to each other, and you only have to complete the lattice.