Export XYZ of periodic system

Dear All

I modified XYZ Exporter (https://community.accelrys.com/thread/1752) to get XYZ coordinates of atoms in one periodic box (shown in the visualizer) of a infinite system, but I got the following error:

"Cannot operate upon infinite SymmetrySystem (function/property "Atoms") at -e line 42"

at line

my \$atoms = \$doc->Atoms;

Could anyone help me out here?

Thank you.

Jingjing Bu