Meshing a periodic structure

Hello,

I tried to mesh a structure that consists of a cube and some particles. The special thing is that the opposing sides of the cube are equal and need to have exactly the same mesh. So I tried to mesh the surfaces on one side at first and then I used the scheme copy to mesh the surfaces on the other side. The problem is that cubit crashes most time by copying the mesh of not convex surfaces. Is there any other option to get the same mesh on the opposing sides?

Here a some screenshots of an example cube

Thanks

Is there any news on this problem? I would also be interested!