HI All

I'm using CLAYFF to simulate a periodic crystal. I tried to geometry optimize the structure, but I got the following error:

The bond increment charging engine has failed to calculate charges for 2 particles.

There are missing or unknown forcefield types.

Unable to calculate energy and gradients.

Geometry optimization finished with an error condition.

I had used this CLAYFF to simulate similar crystal stuctures, it worked fine. For this new structure, I'm almost sure I mannually typed every atom. I don't understand why there are missing or unknown forcefield types. What does "fail to calculate charges for 2 particles" mean? Is there a way to check if every atom is typed?

Thank you.

Jingjing