chem-ts-optimization

You can optimize a molecular transition-state geometry by providing an initial guess structure for Sella-based TS optimization, followed by a finite-difference vibrational analysis to confirm it is a first-order saddle point with exactly one imaginary mode below a cutoff.

A first-order saddle point is a transition-state geometry with exactly one imaginary vibrational mode. Vibrational analysis confirms this by counting imaginary frequencies below a cm^-1 cutoff to validate the optimized structure.

Yes, MLIP backends like MACE or FAIRChem/UMA are supported for scoring and optimizing non-periodic molecular transition-state geometries during the Sella optimization process.

No, this transition-state optimization workflow does not support periodic structures. It explicitly enforces pbc=False, restricting the TS optimization and vibrational analysis to non-periodic molecular systems.

The workflow generates ts_optimized.xyz containing the final geometry and ts_optimization_results.json with structured outputs including n_imag_below_cutoff and is_first_order_saddle.