# What does occupations='tetrahedra' mean in Quantum ESPRESSO?

I am trying to understand Quantum ESPRESSO input file, line by line. So far everything seems pretty easy to understand. However, I do not know what occupations='tetrahedra' means?

I saw that it should be used when calculating the density of states, but I do not know why.

• Somewhat relevant: mattermodeling.stackexchange.com/q/2414/671 Not proposing it as a duplicate, since a) the answer to that question doesn't address 'tetrahedra', and b) it might be beneficial to separate 'tetrahedra' into its own question (this one). – Anyon Jul 12 at 17:32
• Seems to be addressed partially here: quantum-espresso.org/Doc/INPUT_DOS.html – Anyon Jul 12 at 17:33
• +1. Welcome to our new community and thank you for contributing your question here! We hope to see much more of you in the future! I agree with Anyon's comment, and I've made some minor edits to match the format we have for most of our questions here. – Nike Dattani Jul 12 at 17:33