Hello, I am sorry if my question is too basic but I am trying to get the global parameters to describe the dynamics of my protein and I am not really looking for any spin specific parameters. I have data only at 600 MHz. I thought I could run the model-free.py script using diffusion_tensor.init((9e-8, 0.5, 0.3, 60, 290, 100), fixed=False) But then I get : Over-fit spin deselection. RelaxWarning: The spin ':0' has been deselected because of missing structural data. RelaxWarning: The spin ':1' has been deselected because of missing structural data. RelaxWarning: The spin ':2' has been deselected because of missing structural data. RelaxWarning: The spin ':3' has been deselected because of missing structural data. RelaxWarning: The spin ':4' has been deselected because of missing structural data. RelaxWarning: The spin ':5' has been deselected because of missing structural data. and so on for all my 75 residues. I dont think I can use #diffusion_tensor.init(10e-9, fixed=false) because it complains of a very massive grid search which cannot be run. Is there an easier way to optimise the tm or is there an entirely different approach to get the global parameters for a molecule ? Any guidance will be helpful. Thanks for your time. -- Shantanu S. Bhattacharyya Grad Student, Biological Sciences Carnegie Mellon University url : http://esesbee.com