Hello, I would like to add the orientation matrix information in the cbf file. Following the description in sections 3.2.2.2.3 of IUCr (G), I added the following lines in the cbf header: _diffrn_orient_matrix_type ub_matrix_test _diffrn_orient_matrix_UB_11 0.083424 _diffrn_orient_matrix_UB_12 -0.076007 _diffrn_orient_matrix_UB_13 -0.078787 _diffrn_orient_matrix_UB_21 -0.103374 _diffrn_orient_matrix_UB_22 -0.075939 _diffrn_orient_matrix_UB_23 -0.01146 _diffrn_orient_matrix_UB_31 -0.034434 _diffrn_orient_matrix_UB_32 0.043832 _diffrn_orient_matrix_UB_33 -0.156476 When I try to read back the values with: get_orientation_matrix() I get the following error: UBm = cbf_handle.get_orientation_matrix() File "~/CCTBX/cctbx_plus_build/lib/pycbf.py", line 3915, in get_orientation_matrix return _pycbf.cbf_handle_struct_get_orientation_matrix(self) Exception: CBFlib Error(s): CBF_NOTFOUND If I use set_orientation_matrix() to write the cbf file, I get a similar error. Does anyone have any suggestion on how to solve this? Thanks in advance, Carlo Vecchini -- This e-mail and any attachments may contain confidential, copyright and or privileged material, and are for the use of the intended addressee only. If you are not the intended addressee or an authorised recipient of the addressee please notify us of receipt by returning the e-mail and do not use, copy, retain, distribute or disclose the information in or attached to the e-mail. Any opinions expressed within this e-mail are those of the individual and not necessarily of Diamond Light Source Ltd. Diamond Light Source Ltd. cannot guarantee that this e-mail or any attachments are free from viruses and we cannot accept liability for any damage which you may sustain as a result of software viruses which may be transmitted in or with the message. Diamond Light Source Limited (company no. 4375679). Registered in England and Wales with its registered office at Diamond House, Harwell Science and Innovation Campus, Didcot, Oxfordshire, OX11 0DE, United Kingdom