[Chimera-users] turning kdssp off

Dear Chimera users, is there any way to turn the secondary structure assignment (kdssp) off? I am transforming a set of coordinates from a MD trajectory into electron density. I collapsed many frames of the trajectory into a single file, meaning there are many unphysical overlaps (I only care about the density). Problem is, that the PDB file I am opening is rather large (couple of millions of atoms) and kdssp gets absolutely stuck on it. I would appreciate some help. Best regards, Matt