Porting fragmentation methods to GPUs using an OpenMP API: Offloading the resolution-of-the-identity second-order...

Area of Science:

• Computational Chemistry
• Quantum Chemistry
• High-Performance Computing

Background:

• The resolution-of-the-identity second-order Møller-Plesset perturbation (RI-MP2) method is crucial for accurate electronic structure calculations.
• Scaling limitations of RI-MP2 hinder its application to large molecular systems.
• Graphical Processing Units (GPUs) offer massive parallelism for accelerating computationally intensive tasks.

Purpose of the Study:

• To accelerate the RI-MP2 method by off-loading computations onto GPUs.
• To integrate GPU-accelerated RI-MP2 into the GAMESS electronic structure program and the effective fragment molecular orbital (EFMO) framework.
• To evaluate the performance and scalability of the GPU-accelerated RI-MP2 method.

Main Methods:

• Implementation of RI-MP2 calculations on GPUs using OpenMP Application Programming Interface.
• Development of a novel scheme to maximize GPU data digestion and linearize CPU-GPU data transfer.
• Interfacing GAMESS Fortran code with NVIDIA cuBLAS and cuSOLVER libraries for efficient matrix operations.
• Utilizing NVIDIA V100 GPUs and IBM P9 CPUs for computational acceleration.

Main Results:

• Standalone GPU RI-MP2 achieved speedups of up to 7.5× on fullerenes.
• A single Summit node (6 V100s) computed a 175-water molecule cluster's RI-MP2 energy in ~0.85 hours.
• GPU RI-MP2 in the EFMO framework demonstrated near-linear scaling with a large number of GPUs for a complex nanoparticle system.
• High parallel efficiencies (98.0% and 96.1%) were observed with 2304 and 4608 V100s, respectively.

Conclusions:

• GPU acceleration significantly enhances the performance of the RI-MP2 method for large-scale electronic structure calculations.
• The developed GPU RI-MP2 implementation is efficient both as a standalone method and within the EFMO framework.
• This work enables more accurate and efficient computational studies of larger and more complex molecular systems.