Hi everyone, Thanks Ed and Sébastien for your answers. The minimization with the ellipsoid tensor took good 31 rounds and finally it passed the convergence test. Now I face anther issue, I couldn't make the program run through the model selection. It crashes during the Monte Carlo simulation. Apparently it has some trouble reading in the back calculated data. Here I attached the last steps before crashing I'll appreciate any feedback. Thanks in advance Daniel relax> monte_carlo.create_data(method='back_calc') Traceback (most recent call last): File "/soft/group/relax/relax-1.3/relax", line 358, in ? Relax() File "/soft/group/relax/relax-1.3/relax", line 126, in __init__ self.interpreter.run(self.script_file) File "/soft/group/relax/relax-1.3/prompt/interpreter.py", line 287, in run return run_script(intro=self.__intro_string, local=locals(), script_file=script_file, quit=self.__quit_flag, show_script=self.__show_script, raise_relax_error=self.__raise_relax_error) File "/soft/group/relax/relax-1.3/prompt/interpreter.py", line 533, in run_script return console.interact(intro, local, script_file, quit, show_script=show_script, raise_relax_error=raise_relax_error) File "/soft/group/relax/relax-1.3/prompt/interpreter.py", line 429, in interact_script execfile(script_file, local) File "full_analysis_last.py", line 197, in ? dAuvergne_protocol(diff_model=DIFF_MODEL, mf_models=MF_MODELS, local_tm_models=LOCAL_TM_MODELS, pdb_file=PDB_FILE, seq_args=SEQ_ARGS, het_name=HET_NAME, relax_data=RELAX_DATA, unres=UNRES, exclude=EXCLUDE, bond_length=BOND_LENGTH, csa=CSA, hetnuc=HETNUC, proton=PROTON, grid_inc=GRID_INC, min_algor=MIN_ALGOR, mc_num=MC_NUM, conv_loop=CONV_LOOP) File "/soft/group/relax/relax-1.3/auto_analyses/dauvergne_protocol.py", line 401, in __init__ self.interpreter.monte_carlo.create_data() File "/soft/group/relax/relax-1.3/prompt/monte_carlo.py", line 77, in create_data monte_carlo.create_data(method=method) File "/soft/group/relax/relax-1.3/generic_fns/monte_carlo.py", line 69, in create_data data = create_mc_data(data_index) File "/soft/group/relax/relax-1.3/specific_fns/model_free/main.py", line 1175, in create_mc_data value = self.back_calc_ri(spin_index=global_index, ri_label=spin.ri_labels[j], frq_label=spin.frq_labels[spin.remap_table[j]], frq=spin.frq[spin.remap_table[j]]) File "/soft/group/relax/relax-1.3/specific_fns/model_free/main.py", line 452, in back_calc_ri if hasattr(cdp, 'diff_tensor') and (cdp.diff_tensor.type == 'spheroid' or cdp.diff_tensor.type == 'ellipsoid') and (not hasattr(spin, 'xh_vect') or not spin.xh_vect): ValueError: The truth value of an array with more than one element is ambiguous. Use a.any() or a.all() Dr. Daniel Pérez Institut für Molekularbiologie und Biophysik Schafmattstrasse 20 ETH-Hönggerberg, HPK G 5 CH-8093 Zürich Phone: +41 44 633 25 37 E-mail: daniel.perez@xxxxxxxxxxxxxxxx