Build VESTA supercell with two domains

Question

I would like to build a supercell with vesta.

As a starting point I have a unit cell with polarization, I used it as my first structure in Vesta.

File -> New Structure -> Import

The supercell should consist of two unit cells of the same type. The second unit cell should be shifted and rotated 90°. Thus i will get two domains with different polarization. I tried this with

Phase -> Import

I set the first element of the global coordinate system to the length of the unit cell to shift the second structure, I deleted all duplicated atoms. But how can I rotate the second structure and how can I merge these two to one supercell?

Has somebody experiences with VESTA?

Thanks a lot for any help.

Answer 1

I want to rotate the second structure $\theta=90^{\circ}$ about the x-axis. The rotation matrix is given as

$$R_x(90^{\circ})=\begin{pmatrix}1&0&0\\0&0&-1\\0&1&0\end{pmatrix}.$$

Start a new Vesta window:

New Structure-> Structure parameters -> Import

Import your first structure/origin unit cell. Maybe one have first to shift the cell, so that the main atom is placed in the origin (edit Unit cell-> Transform ->Origin shift p).

Next add the second structure: Phase -> Import

• One have to shift the second structure, chose the second Phase, edit the Global coordinate system for example x = length of unit cell.
• Go to Unit cell, check if the second phase is chosen, go to Transform, insert the rotation matrix (for example $R_x(90)$)
• Structure parameters -> Remove duplicate atoms. Since the periodic boundaries atoms were counted twice one can also lower the boundaries from $1 \to 0.99$ or the more easy way just delete later the redundant atoms (on the intersecting plane) in your xyz-output file.
• Delete the bonds (Ctrl - B-> klick on the bonds and Delete) so that we just have the atom positions as the input for the supercell.

Now we have two unit cells with different polarization. We can save it and use is for further calculations as the basic for the supercell.