Select Units
Turn on measurements
  B6: How to measure a distance.
Distance measurements are similar in function to labeling an atom as both involve modifying the behavior of the mouse. Distance measurements require the selection of the two atoms with the mouse with double clicks on the atom. Because distance measurements require two clicks, you can still identify atoms with one click while measuring distances. Follow the steps below to display inter-atomic distances in angstroms:

First change the units to Angstroms:

  1. Open the menu by clicking the right mouse button.
  2. Scroll down to "Measurement"
  3. Select "Distance units Angstrom (2nd from bottom).
Now turn on distance measurements:
  1. Open the menu by clicking the right mouse button.
  2. Scroll down to "Measurement"
  3. Select "Click for distance measurement".
Now double click on one atom, and then another. The distance between the two should be diplayed on the molecule. You can toggle the display of the distances, as the first selection under the "Measurement" selection. You also have options of listing the measurements in a separate window or delete them.