When working with complex molecular systems, it is often necessary to repeatedly check specific distances, angles or torsion angles between atoms. However, a common frustration among molecular modelers is the need to re-measure these values after every view change or manipulation. If this sounds familiar, here’s a simple tip with SAMSON that can help you track these measurements effectively: use labeling.
SAMSON provides a tool called the Measure editor, accessible via the left-side menu (look for a ruler icon) or by pressing Ctrl/Cmd + M. This tool allows you to:
- Click on a bond to display its length
- Select two atoms to show their distance
- Choose three atoms to show the angle they form
- Select four atoms to visualize their torsion angle
By default, these measurements are temporary and disappear when a new measurement is made. That means if you’re rotating or minimizing your molecule and want to keep tracking key distances, you’ll need to reapply the tool repeatedly—unless you save them.
Saving Measurements As Labels
To keep a measurement visible, press Enter after making it. This converts it into a label that is stored in the document. Labeling not only persists your measurement, it also makes it accessible from multiple parts of the interface, including the Document view and the Inspector.
Once saved as labels, these measurements:
- Survive viewport changes
- Automatically update if atom positions or charges change
- Can be customized in appearance (color, font, size, offset)
Why It Matters
If you’re performing interactive simulations, real-time minimizations, or simply navigating large molecules, retaining key measurements as labels is a small step that can prevent errors and save frustration. Labels allow you to instantly track changes and document specific chemical properties, which is particularly useful when collaborating or reviewing molecular models.
Visual Customization
In the Inspector, you can:
- Change the color of distance lines and angle planes
- Modify text color and font
- Reset colors or fonts to defaults when needed
Whether you’re highlighting specific interactions for visualization or publication, or just want a cleaner view of your molecule, these customization features can significantly enhance your workflow.
Measurement Precision
Label precision can be adjusted in Preferences > Rendering > Labels. There, you can set the number of decimal places shown for distances and angles. This is useful when dealing with fine structural alterations or comparing theoretical and experimental values.
To learn more about measurement tools, labels, and customization in SAMSON, visit the full documentation page here: https://documentation.samson-connect.net/users/latest/measuring/.
SAMSON and all SAMSON Extensions are free for non-commercial use. You can download SAMSON at https://www.samson-connect.net.