Calculate the first 2 excited states of the Oxygen atom by using the CASSCF method with appropriate basis sets then compare with the experimental values.

 

 

unit:eV

 

Will there has Transition State ( TS ) between the two structures? If so, what would be the barrier height between them?

groud state                                               TS

              

 

 

Optimize the first excited state of two structures, and plot a simple energy level diagram based on the energy difference.