The experimental section of a manuscript if the manuscript is
               submitted in parts. As an alternative see _publ.manuscript_text
               and _publ.manuscript_processed.
               The _publ.section_exptl_prep, _publ.section_exptl_solution and
               _publ.section_exptl_refinement items are preferred for
               separating the chemical preparation, structure solution and
               refinement aspects of the description of the experiment.