[phenixbb] convergence in Phenix real space refinement

Hi, I'm curious to know when convergence has been obtained in phenix_real_space_refine. I see the number "moved from start" in the log file and assume that once it doesn't change much after several macro cycles then convergence has been obtained when refining a structure. True? What is that value based on, the RMSD between the initial structure and the final structure? I didn't find this documented in the 2018 publication of the program. Many thanks, Rob