Hi, I'm facing a new challenge while working with cctbx: Imagine a set of (possibly incomplete) measured intesities, or integrated intensities from xrd powder patterns (I_obs) and a fitting crystal symmetry (xtal_symm). Now if I want to check if a given structure would generate the same intensities. (--> low R1) the following code exibits the problem: # -*- coding: utf-8 -*- from __future__ import division from cctbx import xray from cctbx import crystal from cctbx.array_family import flex from libtbx import Auto obs_file = "Test.hkl" # in shelx hklf4 format xtal_symm = crystal.symmetry( unit_cell=(4.000, 5.4321, 7.531, 90.0, 90.0, 90.0), space_group_symbol="P mm2") trial_structure = xray.structure( special_position_settings=crystal.special_position_settings( crystal_symmetry=xtal_symm), scatterers=flex.xray_scatterer([ xray.scatterer( label="Si", site=(0.0,0.0,0.0), u=0.2)])) # load (integral) intensities from diffraction data from iotbx import reflection_file_reader rfl = reflection_file_reader.any_reflection_file("amplitudes="+obs_file, ensure_read_access=True) I_obs = rfl.as_miller_arrays(crystal_symmetry=xtal_symm, force_symmetry=False, merge_equivalents=True, base_array_info=None)[0] I_obs = I_obs.discard_sigmas() f_obs = I_obs.as_amplitude_array() f_calc = trial_structure.structure_factors(d_min=1.0).f_calc() f_calc.merge_equivalents() R1 = f_calc.r1_factor(f_obs, scale_factor=Auto, assume_index_matching=False) gives: " assert other.indices().size() == self.indices().size() AssertionError " Is there some way to get the R1_factor for this kind of scenario? Cheers and thanks in advance, Jan