remarks ../xtalmr/unitcell.inp

{===>}structure @rigid.psf end                       {*Read structure file.*}

{===>}coor @rigid.pdb                                   {*Read coordinates.*}
  
delete                                        {*Keep protein backbone only.*}
  selection=( not (  name ca or name n or name c  ) ) 
end

xrefin
{===>}                                             {*Unit cell for crystal.*}
   a=44.144 b=164.69 c=70.17 alpha=90. beta=108.50 gamma=90.
   
end


vector do ( segid="1" ) ( all )

   {*The next two statements would have to be repeated for each space group*}
   {*operator.  Just increase the segment identifier for each new symmetry *}
   {*mate.                                                                 *}
duplicate selection=( segid "1" ) segid="2" end
coor symmetry=(-x,y+1/2,-z) selection=( segid "2" ) end

       {*The next statement translates the molecules into the standard unit*}
       {*cell.                                                             *}
coor fractionalize end
vector do (x=mod(x+10,1)) ( all )
vector do (y=mod(y+10,1)) ( all )
vector do (z=mod(z+10,1)) ( all )
coor orthogonalize end

                    {*A new structure file and coordinate file are written.*}
write coordinates output=unitcell.pdb end
write structure output=unitcell.psf end

stop