Defaults are given in square brackets in this documentation; '#' indicates that the program will generate a suitable default value based on the rest of the available information. Continuation lines are flagged by '=' at the end of a line, the instruction being continued on the next line which must start with four spaces. Other lines beginning with four spaces are treated as comments, so blank lines may be added to improve readability. All characters following '!' or '=' in an instruction line are ignored, except after TITL, SYMM or EQIV (for which continuation lines are not allowed).
The '.ins' file may include an instruction of the form: +filename (the '+' character MUST be in column 1). This causes further input to be taken from the named file until an END instruction is encountered in that file, whereupon the file is closed and instructions are taken from the next line of the '.ins' file. The input instructions from such an 'include' file are not echoed to the '.lst' and '.res' file, and may NOT contain FVAR, BASF, EXTI or SWAT instructions or atoms (except inside a FRAG...FEND section) since this would prevent the '.res' file from being used unchanged for the next refinement job (after renaming as '.ins').
The '+filename' facility enables standard fragment coordinates or long lists of restraints etc. to be read from the same files for each refinement job, and for different structures to access the same fragment or restraint files. One could also for example store the LATT and SYMM instructions for different space groups, or neutron scattering factors for particular elements, or LAUE instructions followed by wavelength-dependent scattering factors, in suitably named files. Since these 'include' files are not echoed, it is a good idea to test them as part of an '.ins' file first, to check for possible syntax errors. Such 'include' files may be nested; the maximum allowed depth depends upon the operating system and compiler used. Note that on some (e.g. IBM mainframe) computers, 'filename' is a dummy name (DDNAME) which must be defined in the JCL or REXX macro used to submit the job.
To Atom Lists and Least-Squares Constraints
To Fourier, Peak Search and Line Printer Plots
Back to Twinned Crystals and Refinement against Powder Data
Back to Table of Contents