moltemplate example question

Dear lammps-users,

I am looking at the example of carbon nanotube for moltemplate which is a pre-processing tool for LAMMPS, and I have a question with the part of building graphene walls.
For this line:

unitcells[*][*].move(-24.595121467478, -14.91, 0.000)

How does the writer find out the distance need to be moved? Y-direction is simple, but I do not know how to find out the X-direction moving distance.
Thank you!

Miao-Chun Wang