It has a CdI2 structure, so z should be close to 0.25.

Thank you for your help!

I also found the 0.25 but that did not give me a 90-degree angle of the octahedral coordination of the S atoms around the Mo atom (and I found a paper that displays the structure that way). I chose now Z to be roughly 0.105 which gives the distance of 0.21 between S atoms...which is slightly less than your suggested 0.25. Not 100% sure which exact value is the correct one but it works for my purposes.

Again, thank you!