At the start of the script you will notice a number of Analysis variables. Unless you know what you are doing, you should only change the DIFF_MODEL variable to the following:
The MF_MODELS and LOCAL_TM_MODELS variables specify which model-free models will be used in the analysis. But, as the full protocol behind this script which is designed to find the solution of the universal set (see section 7.7.2 on page ) expects that all these models are present, you should not change these variables. If you do remove some model-free models, you should fully expect to see artificial motions which you will not be able to distinguish from the real molecular motions.
The next variables GRID_INC and MIN_ALGOR are related to the optimisation of the model-free models. These should also not be touched unless you fully understand the consequences (and have read d'Auvergne and Gooley (2008b)). The variable MC_NUM specifies the number of Monte Carlo simulations. This number can be increased but, for realistic parameter errors in your publication, it should not set lower than 500 simulations.
Finally the CONV_LOOP variable is designed to make your life easier. If left at the value of True, the script will iterate until convergence (see Figure 2 in d'Auvergne and Gooley (2008c) to understand this concept). If changed to False, then you will need to run the script manually for the 15 or so iterations of each diffusion model, and then repeat this for all diffusion models II to V.
The relax user manual (PDF), created 2016-10-28.