#qnan problem

When I was using p p p bc every thing was good. But I need to apply p f p. This bc produces #QNAN instead of numbers. Its a variable problem but I am not able to solve it. Please help.

Nobody will be able to help you if you don't provide information to reproduce your problem. Axel.

I have constructed polypropylene using Material studio and using it in LAMMPS. When I use p p p (boundary)and calculate energies, temperature pressure and many more, It gives me values in numerical values. But I need to apply p f p condition. So when I do it, result shows #qnan instead of number.
And I am not able to correct it many try.
Plz give some help.

Your description is useless.
One would have to be a mindreader to find out what you did wrong. There are just too many possible reasons.

You will have to provide the exact inputs (ideally together with log files) so that people can run them without too much effort.

Otherwise you’ll be stuck with figuring it out by yourself.