A question of crystal representation

[Luis Ferreira]

A question of crystal representation.

I'm a secondary school teacher here in Portugal. I want to represent a
CuSO4.5H2O crystal rendered in POVRAY for didactical proposes.

If I need to present an organic molecule, I search for a pdb file in the net and
then export it in POVRAY format, make the render image, and then print it in a
transparent film to use in a retroprojector.

With crystals of inorganic compounds I don't know how do the same thing.

My problem is:
-I don't know what software to use (free!) in order to represent crystal
structures.
-I don't know what kind of files to use for this propose.
-I don't know where I can get these files (free!).

I tried the "PowderCell" program, but I am unable to get powdercell, xhelx or
ICSD files of CuSO4.5H2O (or maybe others that I'll need).  What I did find  in
the net was Ortep-3, but I needed a password.

Please, help me.

Luis Ferreira