dihedral angle

sir,
   sir i wanted to know about, how i will check in my system any dihedral
angle is present or not? and how i will calculate angle between atom ?

thank u

sir,
   sir i wanted to know about, how i will check in my system any dihedral
angle is present or not?

i don't understand the question.
is the about LAMMPS will see if you have a dihedral defined?
or is it about how you prepare input for it?

and how i will calculate angle between atom ?

axel.