Ten years after The Tragically Hip's final tour, KHSC and Queen's mark a decade of progress in brain tumour care and research - Queen's University

MainMolecular simulation is a cornerstone of material discovery and molecular design. While the prediction of energy and forces is often sufficient for structural dynamics, advanced computational chemistry workflows often depend on the molecular Hessian1,2. By describing the local curvature of the potential energy surface (PES), the Hessian is foundational to many computational workflows. Second-order geometry optimization relies on the curvature information to rapidly and reliably converge to equilibrium structures3. Transition state searches and extrema classification depend on the Hessian to correctly identify saddle points and reaction barriers, which are essential for parameterizing reaction rates and microkinetic models for longer time- and length-scale simulations4. Furthermore, mode-following transition state search methods directly leverage the curvature information to locate the transition states5. Finally, vibrational analysis uses Hessian eigenvalues to compute zero-point energy (ZPE) corrections and thermodynamic free energies bridging the gap from static molecules to nonzero temperature observables6.

Lawrence Livermore National Laboratory researcher Isaiah Santistevan led the development of three-dimensional simulations exploring how a nuclear device could deflect or disrupt an asteroid threatening Earth. Credit: Blaise Douros/LLNL Lawrence Livermore National Laboratory (LLNL) researchers are developing three-dimensional simulations to examine how a nuclear device could be used to deflect or potentially disrupt an asteroid threatening Earth.