Changed definition of self._groupselections_ref_coords64

[DhanushkaWeerakoon]

Changed self.reference.select_atoms(…) (line 736) to self.reference.universe.select_atoms(…)

Fixes #2797

Changes made in this Pull Request:

• Changed self.reference.select_atoms(…) in definition of self._groupselections_ref_coords64 within rms.RMSD class (line 736) to self.reference.universe.select_atoms(…)

LLM / AI generated code disclosure

LLMs or other AI-powered tools (beyond simple IDE use cases) were used in this contribution: no

PR Checklist

• [ y ] Issue raised/referenced?
• [ n ] Tests updated/added?
• [ n ] Documentation updated/added?
• [ y ] package/CHANGELOG file updated?
• [ y ] Is your name in package/AUTHORS? (If it is not, add it!)
• [ y ] LLM/AI disclosure was updated.

Developers Certificate of Origin

I certify that I can submit this code contribution as described in the Developer Certificate of Origin, under the MDAnalysis LICENSE.

---

📚 Documentation preview 📚: https://mdanalysis--5366.org.readthedocs.build/en/5366/

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 93.84%. Comparing base (2a3d7b2) to head (03fb4b5).

Additional details and impacted files

@@             Coverage Diff             @@
##           develop    #5366      +/-   ##
===========================================
- Coverage    93.85%   93.84%   -0.01%     
===========================================
  Files          182      182              
  Lines        22499    22499              
  Branches      3200     3200              
===========================================
- Hits         21117    21115       -2     
- Misses         921      922       +1     
- Partials       461      462       +1     

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.