Parameter and topology files used in X-PLOR/CNS refinement.
_pdbx_xplor_file.serial_no 1 _pdbx_xplor_file.pdbx_refine_id 'x-ray' _pdbx_xplor_file.param_file parm_hol.dat _pdbx_xplor_file.topol_file topol_hol.dat