Fast Shepard interpolation on graphics processing units: potential energy surfaces and dynamics for H + CH4 → H2 +...

Area of Science:

• Computational Chemistry
• Chemical Physics
• Reaction Dynamics

Background:

• Potential energy surfaces (PESs) are crucial for understanding chemical reactions.
• Evaluating PESs computationally can be time-consuming.
• Graphics Processing Units (GPUs) offer parallel processing capabilities that can accelerate computations.

Purpose of the Study:

• To develop and present a fast strategy for evaluating Shepard interpolated potential energy surfaces (PESs) using GPUs.
• To calculate thermal rate constants for a specific chemical reaction using the developed GPU-accelerated PES evaluation.
• To compare results with existing methods and present a revised PES.

Main Methods:

• Shepard interpolation for PES construction.
• Graphics Processing Unit (GPU) acceleration for fast PES evaluation.
• Quantum transition state theory and the multi-layer multi-configurational time-dependent Hartree (ML-MCTDH) approach for rate constant calculations.

Main Results:

• Achieved speed-ups of several orders of magnitude for PES evaluation on the ZFWCZ PES.
• Calculated thermal rate constants for the title reaction.
• Identified the importance of accurately describing anharmonicity around the transition state through a revised PES.

Conclusions:

• GPU acceleration provides a significant speed-up for PES evaluation.
• Accurate calculation of thermal rate constants is sensitive to the description of anharmonicity in the PES.
• A revised PES improves the accuracy of calculated thermal rate constants.