Drawing crystal structures like inverse spinel oxides such as CoFe2O4 can be challenging, especially if you're encountering issues with software. You can use a program like VESTA, but sometimes manual adjustments are necessary. Here's a step-by-step guide to drawing the crystal structure:

1. Open VESTA or a similar crystal structure visualization software.

2. Import the crystallographic data for CoFe2O4, which should be available from databases like the Crystallography Open Database (COD).

3. Once you've imported the data, you should see the crystal structure. However, as you mentioned issues with octahedral positions, you might need to adjust them manually.

4. To visualize the octahedral positions, look for the coordination polyhedra tool. In VESTA, this is typically located in the "Edit" menu or as an icon resembling a polyhedron.

5. Select the central cation in your inverse spinel oxide structure (in CoFe2O4, it's Co2+). Create an octahedral coordination polyhedron around it.

6. Adjust the size and shape of the octahedron to fit the crystal structure accurately. You may need to move individual atoms to correct positions.

7. Repeat the process for the octahedral positions around the other cations (Fe3+ in CoFe2O4).

8. Once you've manually adjusted the octahedral positions, save the crystal structure in the desired file format.

Remember that inverse spinel oxides can be complex due to the arrangement of cations in octahedral and tetrahedral sites. Adjusting them accurately may require patience and a good understanding of crystallography. If you continue to encounter issues, consider seeking assistance from a crystallographer or materials scientist who has experience with these types of structures.

Dear Manpreet,

you will find a description of the spinel structure in the attached file and some other information on spinel ferrites. But perhaps you want a software to draw the structure... I have not such software to propose.

Best regards.

Philippe.