Hi Daniel, Not dumb, it's easy to get these things messed up! Yes, "protein" is an atomspec, as is "#6/H". The protein part isn't needed for cartoon style except to limit a broader spec that might also include nucleic acid chains (assuming you don't want it to also apply to those). In general, however, you can combine atomspecs with operator symbols: & for logical AND, | (vertical bar) for logical OR, e.g. car style #6 & protein modeh default arrows f xsect oval width 1 thick 1 Combinations discussed here: <http://rbvi.ucsf.edu/chimerax/docs/user/commands/atomspec.html#combinations> I hope this helps, Elaine ----- Elaine C. Meng, Ph.D. UCSF Chimera(X) team Department of Pharmaceutical Chemistry University of California, San Francisco

On Oct 19, 2020, at 7:44 PM, Daniel Asarnow <asarnow@msg.ucsf.edu> wrote:

Ah, I'm dumb, "protein" is taking the atom-spec slot.

Best, -da

On Mon, Oct 19, 2020 at 7:35 PM Daniel Asarnow <asarnow@msg.ucsf.edu> wrote: Hi, When I use cartoon style with an atom spec, ChimeraX reports "expected a keyword" error.

This is the "licorice" example from the documentation, which only works without an atom spec. car style protein modeh default arrows f xsect oval width 1 thick 1 car style #6/H protein modeh default arrows f xsect oval width 1 thick 1

Is my syntax wrong?

Thanks, -da