One challenge molecular modelers face regularly is documenting and tracking geometrical parameters—bond lengths, angles, and torsion angles—during interactive modeling sessions. Whether you’re refining structures manually, running minimizations, or preparing presentations, keeping these measurements visible and editable can be essential.
In SAMSON, the Measure editor offers a flexible way to perform on-the-fly measurements and record them as editable labels. This post shows how to go beyond temporary measurements and turn your observations into persistent, document-integrated annotations using measurement labels.
Temporary vs. Persistent Measurements
By default, when using the Measure editor (activated with Ctrl/Cmd + M), measurements are temporary. Click on a bond to see its length; click on two, three, or four atoms to observe distances, angles, or torsions. These measurements are always visible regardless of zoom level but disappear upon the next measurement interaction.
That’s where labels come in. By pressing the Enter key right after making a measurement, you convert it into a persistent label that becomes part of your document. This way, you can:
- Preserve geometrical data across modeling sessions
- Toggle visibility depending on zoom
- Change their appearance and position
- Export and share documents with annotated measurements
Why Use Labels?
Think of measurement labels as molecular Post-it notes: they help you track important details that may evolve during modeling. The benefits of using labels include:
- Automatic updates: If atoms involved in a measurement move, the value updates in real time.
- Integration: Saved labels are accessible from the Inspector, where you can even explore projections of measurements on planes.
- Customization: Change colors, text fonts, and even reset them to defaults with just a click.
More Than Just Numbers
Labels aren’t limited to geometric measurements. You can add formal or partial charge labels to atoms using the label editor toolbar (Label > Add label to… > Atoms (formal charges)), making your document even richer in interpretative tools.
Display Preferences and Customization
Customize how labels appear via Preferences > Rendering > Labels. You can set the default font and number of significant digits for all new labels. For individual labels, fine-tune their font, color, and positioning using the Inspector.
To reset specific attributes such as line or text color, simply double-click or use the provided reset button next to the attribute in the Inspector panel.
Conclusion
Measurement labels in SAMSON help you document, analyze, and present your molecular modeling work with clarity. Whether you’re preparing a report or tracking changes during simulation, labels keep your annotations visible, editable, and accurate—even as your molecular system evolves.
To dive deeper, check out the original documentation page: https://documentation.samson-connect.net/users/latest/measuring/
SAMSON and all SAMSON Extensions are free for non-commercial use. You can get SAMSON at https://www.samson-connect.net.