The September 16, 2002 issue of Chemical and Engineering News features
a cover story on the use of computational chemistry in education. The cover shot was
produced by Dr. James Foresman, a Gaussian collaborator,
using the program
reads the output of Gaussian and graphically displays the data. For more instructions on
Molekel and other programs that visualize Gaussian datafiles, go
The picture that you see on the cover describes two different excited states of the
molecule, vanadyl acetylacetonate. The top one is a d-d type transition while the bottom one
could be described as a d-ligand transition. In both of these, the colors represent changes
in electron density in going from the ground state to the excited state. Blue is where the electrons
start and gray is where they finish. Below the bottom figure is a flat surface showing the projection
of all these changes onto one plane.
There are many excited states that could be visualized for this molecule.
Below is a Gaussian input file that would calculate the lowest nine states, produce the output
needed for Molekel, and also perform a Natural Population Analysis on each state: