Simulations need to be run in a large cluster. The simulations here took about 200 * 4 * 2 = 1,600 computing hours, i.e. about a month on a two core computer.
The simulations require using: slurmR, ergmito, and of course, ergm.
To execute a simulation with slurmR, you can simply type
slurmR::sourceSlurm("simulations/02-various-sizes-4-5.R")
Which will create a slurm job and run the simulation file.