The output filter has to accept the following data from its standard input and write them to a file whose name is given as a command line parameter to the filter. VIEWMOL passes the following data groups to the output filter:
$unitcell a b c alpha beta gamma
$coord x1 y1 z1 symbol1 x2 y2 z2 symbol2 ...
$bonds atom1 atom2 bond_order ...
atom2are the numbers of the atoms according to the list in
$coordwhich form the bond.
bond_orderis the actual order of the bond, -2 if the bond is part of a conjugated system, or -1 if it is a hydrogen bond.
$endis passed to the output filter as last line.