The tool convertcrystal is part of the QUAD package and converts crystal files in the format XYZ to an output that is usable for QUAD. The standard crystal structure .cif files can be usually exported to a .xyz file by using software tools like “Diamond” or “Vesta”. convertcrystal executes a script file which can contain following commands line by line. An example should be provided in the Tutorials folder

openxyz filename

opens a .xyz file

savexyz filename

saves a .xyz file

unitcell a b c alpha beta gamma

defines the unit cell structure of the loaded file. The definition of the 6 parameters can be found here: http://en.wikipedia.org/wiki/Fractional_coordinates

printunitcellvectors

prints the current unit cell vectors a,b and c

atomdistance d

Sets the distance limit in which the atoms are treated identical. (default: d=0.1A)

findneighbors

just prints the atom and tells how many other atoms at the same crystal position could be found

removeoutside

remove all atoms outside of the unit cell

reduce

removes atoms that sit on the same site in the crystal lattice (e. g. atoms at the corners) the function “removeoutside” should be executed first.

expand min max

expands the unit cell around the borders

sort

sort the atoms for increasing z-coordinate

rotatex angle

rotates crystal and the unit cell coordinates around x-axis

rotatey angle

rotates crystal and the unit cell coordinates around y-axis

rotatez angle

rotates crystal and the unit cell coordinates around z-axis

moveatom atomnr x y z

moves an atom around. if atomnr is -1 then the whole crystal is moved

findcubiccell

trys to find the smallest cubic unitcell of the system. and sets the unit cell accordingly. If this function does not work you have to do it manually by the “unitcell” command.

buildlayers nlayers

prints a script snipplet which contains the coordinates for the atom layers which you can directly use in the lua script. Note that the layer will be build up along z-axis and not around c-axis.

pause

waits for a keypress (enter)

check

checks if there is something outside of the primitive outside of the unit cell and warns In future there will be more checks included