To get a help on the XCrySDen command line options type xcrysden --help. Below is the short description (the same description as printed by the --help option) of XCrySDen command line options.

Usage: xcrysden OPTIONS [FILE|DIRECTORY]

If FILE is "-", then input is read from standard input !!!

OPTIONS are:
-----------             

        -h
   or   --help          help; displays this message


        -v
   or   --version       prints version and exits


        -a           <file>
   or   --attributes <file>    
                        load attributes from file. Attribute file looks
                        like:
                                ELEMENTCOLOR
                                atomic-number1   red1 blue1 green1
                                atomic-number2   red2 blue2 green2
                                ...
                                ELEMENTRADIUS
                                atomic-number1   radius1
                                atomic-number2   radius2
                                ...


        --xsf <file>
   or   --xcr <file>    load structure from XCrySDen's-Structure-File (XSF)
                        formatted file


        --animxsf <file>
   or   --axsf <file>   Animation!!! Load structres from Animation-
                        XCrySDen's-Structure-File (AXSF) formatted file


        --xyz <file>    load structure from XYZ formatted file

        --pdb <file>    load structure from PDB formatted file

        --gzmat  <file> load structure from Gaussian Z-matrix (requires
                        BABEL program)

        --g98_out <file>
                        load structure from Gaussian98 output
                        file. Only single point calculation and
                        optimization run is supported so far. For the
                        optimization run it is possible to render all
                        the structures that were produced during the
                        run.

        --g98_cube <file>
                        load structure from Gaussian98 cube file. The cube
                        file should be produced with the Cube=Cards option.
                        Only scalar cube files are supported, that is,
                        Cube=(Cards,Density) or Cube=(Cards,Orbitals) or
                        Cube=(Cards,Potential). Refer to GAUSSIAN manual
                        for the meaning of this keywords.

                        
        --crystal_inp <file>
                        load structure from CRYSTAL95/98 input file


        --crystal_f9 <file>
                        load structure from CRYSTAL95/98 unit 9

        
        --wien_struct <filehead|file|directory>
                        load structure from WIEN-Struct-File formatted file

                        filehead  = name of struct file without ".struct" 
                                    extension
                        file      = filename
                        directory = name of case directory      


        --wien_kpath <directory>
                        reads "struct" file and renders first Brillouin zone 
                        with special k-points. K-path can be selected
                        interactively by mouse-clicking the special k-points. 
                        User must specify EMIN and EMAX energies and total 
                        number of k-points along the path (this is merely an 
                        estimation of total number of k-points, since
                        XCrySDen tries to get very uniform sampling of 
                        k-points along the path (don't specify WIEN97's 
                        maximum allowed number of k-points, since XCrySDen 
                        maight generate few points more)).


        --wien_renderdensity <directory>
                        reads "struct", "output5" and "rho" files and renders
                        crystalline structure and precomputed charge density.


        --wien_density <direcory>
                        2D or 3D region for charge density calculation can be 
                        interactively chosen by mouse-clicking. XCrySDen 
                        generates "in5" file(s), calculates and renders 
                        charge density either as isolines/colorplanes (2D) 
                        or isosurfaces (3D).


        --wien_fermisurface <directory>
                        Pops-up a task window for Fermi surface creation.
                        After several steps the Fermi surface is hopefully
                        drawn as 3D isosurface. This feature is EXPERIMENTAL,
                        please be careful !!!


        --fhi_inpini <inp.ini-file>
                        load structure from FHI98MD "inp.ini" formated file


        --fhi_coord <coord.out-file>    
                        load structure from FHI98MD "coord.out" formated file


        --pwi  or
        --pw_in   <PWSCF-input file>
                        load structure from PWSCF input file.
                        PWSCF is a planewave package (http://www.pwscf.org/)

        --pwo   or
        --pw_out  <PWSCF-output file>    
                        load structure from PWSCF output file.
                        PWSCF is a planewave package (http://www.pwscf.org/)

        
        -l
        --lights <lights-file>
                        load lights parameters from XCRYSDEN lights file

        -s
        --script <script>
                        load script from file Tcl script