Q. MOs during the geometry optimization

 

A. MOs printed out at the end of the job using "pop=full" may differ from those for the initial geometry in the SAC-CI geometry optimization. For analyzing the nature of the excited state, it is recommended to perform single point SAC-CI calculation at the converged optimized geometry. This is automatically done by "MacroIteration=1".

  During geometry optimization, MOD (Minimum-Orbital-Deformation) algorithm is performed in order to obtain continuous orbital nature during the optimization. In other words, canonical MOs are not used in the optimization process.