9 Exploring Potential Energy Surfaces: Critical Points and Molecular Dynamics

9.2 Improved Algorithms for Transition-Structure Optimization

Transition-structure searches tend to be more difficult (meaning, more likely to be unsuccessful) as compared to minimum-energy (equilibrium) geometry optimizations. Odds of success can be enhanced via an initial guess structure that is determined in an automated way, rather than simply “guessed” by the user. Several such automated algorithms are available in Q-Chem, and are described in this section.