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Semiclassical vibrational spectroscopy with Hessian databases
Riccardo Conte1, Fabio Gabas1, Giacomo Botti1
1Dipartimento di Chimica, Università degli Studi di Milano, via Golgi 19, 20133 Milano, Italy.
The Journal of Chemical Physics
|July 1, 2019
Summary
We developed a new method to speed up semiclassical dynamics simulations for vibrational spectroscopy by creating a database of Hessians. This approach reduces computational cost while maintaining accuracy for complex molecular systems.
Area of Science:
- Computational Chemistry
- Theoretical Chemistry
- Molecular Dynamics
Background:
- Ab initio "on-the-fly" semiclassical dynamics simulations are computationally intensive.
- A key bottleneck is the repeated estimation of the Hessian matrix during simulations.
Purpose of the Study:
- To reduce the computational overhead of semiclassical dynamics simulations.
- To enable the study of larger and more complex molecular systems.
Main Methods:
- Developed a novel approach using a dynamical database of Hessians and molecular geometries.
- Interfaced the method with analytical potential energy surfaces and on-the-fly dynamics.
Main Results:
- Significantly eased the computational overhead of simulations.
- Preserved the accuracy of vibrational spectroscopy results.
- Successfully applied to methane, glycine, and a 46-atom biologically relevant molecule.
Conclusions:
- The dynamical Hessian database approach offers a practical solution for accelerating semiclassical dynamics simulations.
- This method expands the scope of achievable studies to larger molecular systems.
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