Fixed broken examples by adding NULL after stess/atom commands

git-svn-id: svn://svn.icms.temple.edu/lammps-ro/trunk@11786 f3b2605a-c512-4ea7-a41b-209d697bcdaa
Fixed broken basal example

git-svn-id: svn://svn.icms.temple.edu/lammps-ro/trunk@11787 f3b2605a-c512-4ea7-a41b-209d697bcdaa