Summary: Materials Modeling Stack Exchange will begin the nomination stage for a special election on June 8 to bring in your three inaugural pro-tem moderators.
For full details of the process, see the announcement on Meta Stack Exchange. The timeline:
On June 15, if there are four or more candidates, we'll run an election. If not, I'll simply appoint the candidates. (There's a small chance we'll need to remove a nomination, but I doubt that will come up.)
If there is an election, I'll announce the results on meta on June 23.
If you have any questions about the process, please stick them in an answer here.