Hello,

I am trying to estimate end-to-end distance (R) of molecule in Chem3D ver.16.

I selected two farthest atoms, and then went to Structure -> Measurements -> Display distance measurement.

Is this a right way to estimate R of my molecule??

You can calculate distance between any two atoms or length of molecule by selecting the two atoms, which is for away comparing other atom, then chose Measurements from the Structures menu and then select Display Distance Measurement from the sub menu that pops up.

Note:
After selecting the first atom if you move the mouse pointer to any of the atom (that you want to get the distance value) then you will get the distance value of the selected atom and the atom that you point.

- PKI Support