Reactant coordinate based state-to-state reactive scattering dynamics implemented on graphical processing units.

Area of Science:

• Computational Chemistry
• Quantum Dynamics
• Chemical Physics

Background:

• State-to-state quantum dynamics simulations are crucial for understanding chemical reactions.
• Efficient computation is needed for complex molecular systems.
• Graphical Processing Units (GPUs) offer potential for accelerating these calculations.

Purpose of the Study:

• To develop and implement a parallel code for time-dependent wavepacket propagation in reactant coordinates on GPUs.
• To accelerate the transformation of wavepackets between reactant and product Jacobi coordinates.
• To achieve significant speedups in quantum dynamics simulations.

Main Methods:

• Developed a parallel code for time-dependent wavepacket propagation on GPUs.
• Implemented GPU-accelerated wavepacket propagation and coordinate transformation.
• Introduced a novel interpolation procedure to optimize the coordinate transformation computation.
• Tested the code for H+HD and O+HD reactions.

Main Results:

• The code successfully performs state-to-state quantum dynamics calculations on GPUs.
• A new interpolation procedure reduced a five-loop computation to two four-loop computations.
• Achieved average speedups of 57.0 and 83.5 on two different GPU configurations compared to serial CPU computation.
• Obtained differential cross sections for H+HD and state-resolved reaction probabilities for O+HD.

Conclusions:

• The developed GPU-based parallel code significantly accelerates quantum dynamics simulations.
• The novel interpolation method enhances computational efficiency for coordinate transformations.
• This approach provides a powerful tool for studying chemical reaction dynamics with high accuracy and speed.