Charge Analysis

• When we solve the Schrödinger equation the energy is not the only output, we also obtain a wavefunction. The square of the wavefunction gives the electron density which can then be partitioned up and assigned to each atom. The result is that we can determine an atomic charge.
• Go to the results tab and select "charge distribution". A new window will appear select NBO as the type(1.) and color the atoms by charge (2.) Important: you must select the NBO charge distribution not the default Mulliken (which is a poor method for computing charge).

  

• Charges are accurate to 0.01e. Write explicitly in your lab report the charges on the O-atom and H-atoms.
• Take a snap-shot of the coloured image of the charge distribution and include this in your lab report, (hide the numbers so they don't show) be sure to identify the colour range for your colour map..
• When carrying out calculations it is always good to check your results against your expectations. Write a sentence saying what charge (positive or negative) you would expect for O and H and why.
• When you are ready close the molecule window move onto the next step