I would like to draw unit cell structures such as wurtzite and cubic. Is there any free softwares to draw unit cells. Attached image is the model which I want to draw.
A really nice piece of software (and free) that I use is VESTA. It's easy to use and allows importing of data from a large variety of formats. It can export both vector and bitmap images. See link.
The image you show is probably a composite of two different drawings. I don't think any of the software listed by other commenters can do make two different structural drawings simultaneously side-by-side (maybe CrystalMaker can?).
A really nice piece of software (and free) that I use is VESTA. It's easy to use and allows importing of data from a large variety of formats. It can export both vector and bitmap images. See link.
The image you show is probably a composite of two different drawings. I don't think any of the software listed by other commenters can do make two different structural drawings simultaneously side-by-side (maybe CrystalMaker can?).
Yes, VESTA is good. So is Avogadro. If you want "side by side" drawings I would suggest making two images and combining them in a drawing program like GIMP. All free.
Use Vesta (https://jp-minerals.org/vesta/en/download.html), and follow the instructions given in a tutorial for ZnO (a Wurtzite structure) https://www.youtube.com/watch?v=qzqHU_KZ2LE.
Then do the same thing for any unit cell you want, but first, you have to make sure that you have the lattice parameters which can be reliably found on Materials Project website (they do have all the CIFs - Crystallographic Information Files).
So here is what you can do: 1)download Vesta 2)watch the tutorial on how to define the crystal structure 3)found the CIF for your material and put it in Vesta.
Farzad Mohaddes You just have to save the structure made in vesta in any file format like .cif and then input that file with a lammps command like this