yes Ray, I did re-combile it.
After a “make yes-class2” did you re-compile?
I will try to copy and pasting the contents as Adrian suggested and see how it goes.
No, that is not necessary as make yes-class2 already does it.
The only thing to check is whether you successfully compiled it and used the correct executable.
Type lmp_<executable_name> -h and see if you have both harmonic and class2 listed.
Ray
Have you checked the harmonic angle style?
Ray