Hi,
If the sequence window title bar says "[ID: 1]" that means the alignment ID is just "1", not "alignment-1"

However, I don't understand what you are trying to calculate.

If you show only a single sequence as the alignment there is nothing to calculate the % identity with.  You would need the alignment to contain two or more different sequences.

I hope this makes sense.
Elaine
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Elaine C. Meng, Ph.D.                       
UCSF Chimera(X) team
Resource for Biocomputing, Visualization, and Informatics
Department of Pharmaceutical Chemistry
University of California, San Francisco



> On Jul 16, 2024, at 2:49 AM, NUR AIDA SAKINAH via ChimeraX-users <chimerax-users@cgl.ucsf.edu> wrote:
>
> Hai,
> I want to use the sequence identity command in ChimeraX but in the log said "Missing or invalid "src1" argument: Expected alignment-id or [alignment-id]:sequence-name-or-number".
> The input I gave is "sequence identity alignment-1" after open the tools>sequence>show sequence viewer and then select model e.g. #1/a and it show the ID as [ID: 1] but i got error. How to solve this problem?
>
> Hope ChimeraX teams can help. Thank you!