Select the Recompute Spectrum button to recompute the IR spectrum. Get Selection Use this option to choose an atom from the canvas instead of using the Select atom menu. Once you have selected an atom from the canvas, hit the Get Selection option. The atom name and its current mass will appear in the type-in boxes. Use the type-in box to redefine the atomic mass for the atom.
Masses are in a.u.
Select the Apply Mass button to apply the change. Select the Recompute Spectrum button to recompute the IR spectrum. Clear Selection Use this button to clear the selected atoms from the current list. Apply Lorentzian broadening Use this option to change the display of the spectrum from sticks to a curve. The curve is generated by applying a Lorentzian broadening function to the spectral lines.