EXPO2004: General info

Commands and their use

The input file name for EXPO2004 is constituted by the name of the structure to analize followed by the suffix .exp, i.e.

name.exp

The input consists of a sequence of commands, directives and comments. The commands are headed by '%' character and directives must follow the related command.

For the default run see Example 1.
EXPO2004 recognizes the following commands:

%WINDOW	Graphic window is required
%NOWINDOW	Graphic window is suppressed
%STRUCTURE string	This command is used to specify the name of the structure to investigate. The program creates the name of the files adding the appropriate extension to the structure name. The file names are: string.bin -> binary file string.out -> output file If this command is not used the default string "STRUCT" (instead of the name of the structure) is used to create file names
%JOB caption	A caption is printed in the output
%INITIALIZE	Initialize the direct access file (to ovewrite previous results and data)
%DATA	Data input routine
%NTREOR	Indexing routine
%EXTRACTION	Integrated intensities extraction routine
%NORMAL	Normalization routine
%INVARIANTS	Invariants routine
%PHASE	Converge-tangent routine
%FOURIER	Fourier/Least-Squares routine
%MENU
%END	End of the input file
%CONTINUE	The program runs in default conditions from the last given command up to the end
%PATTERSON	Patterson map calculation routine
%RECYCLE	Extraction recycle routine
%DIRECT	"direct-space" routines

Directives are described in the sections dedicated to the various routines.
All commands and directives are in free format (between columns 1-80) and are case independent. Only the first four characters are significant. The keywords can start in any position. If the first non-blank character is ">", then the record is interpreted as a comment.
EXPO2004 preserves intermediate results in the file named name.bin (binary file or project file). For example, if invariant estimates have been already obtained during a previous run of EXPO2004, in a new run the command %INVARIANTS can be omitted.

Commands can be given in any order, under the following conditions:

first routine used must be DATA, if it has not been used in a previous run;
NTREOR routine must be used if the "PEAKSEARCH" directive is activated in DATA or an external file of peak positions is supplied;
EXTRACTION routine must be used to extract integrated intensities from the diffraction pattern, if a reflections file is not supplied by the user;
NORMAL must be used if reflections file has been supplied or EXTRACTION step has been performed
INVARIANT routine has no meaning if diffraction moduli are not normalized;
PHASE routine has no meaning if no triplets have been calculated;
FOURIER routine cannot run before PHASE routine (unless a fragment information is supplied by the user; in this case only DATA, EXTRACTION and FOURIER commands are needed).

The minimal information needed by EXPO2004 for a full run is constituted by (see Examples):

cell parameters (not necessary if N-TREOR program is used)
space group symbol (not necessary if the Space Group Determination procedure is applied using "findspace" directive)
cell content
diffraction pattern (or reflections if an external reflection file is provided by any profile fitting program)
wavelength
type of radiation (if neutron or synchrotron data have been used; home diffractometer data is the default).

EXPO2004 prints results in a file named name.out.
Many files can be produced by means of the graphic interface (see File -> Export).