Quantum Chemistry on GPUs

April 1st, 2008

Ivan Ufimtsev and Todd Martínez at the University of Illinois at Urbana-Champaign have implemented an efficient method of calculating two-electron repulsion integrals over Gaussian basis functions on the GPU. Virtually all modern quantum chemical calculations require evaluating millions to billions of these integrals. This problem turns out to be well-suited to the massively parallel architecture of GPUs by an appropriate partitioning of the problem. A benchmark test performed for the evaluation of approximately one million (ss|ss) integrals over contracted s-orbitals showed that a naïve algorithm implemented on the GPU achieves up to 130-fold speedup over a traditional CPU implementation on an AMD Opteron. Subsequent calculations on a 256-atom DNA strand show that the GPU advantage is maintained for basis sets including higher angular momentum functions. (Quantum Chemistry on Graphical Processing Units. 1. Strategies for Two-Electron Integral Evaluation, Ivan S. Ufimtsev and Todd J. Martínez, J. Chem. Theory Comput., 4 (2), 222 -231, 2008. doi:10.1021/ct700268q)

Accelerating Resolution-of-the-Identity Second-Order Møller-Plesset Quantum Chemistry Calculations with Graphical Processing Units

February 11th, 2008

In this paper we describe a modification of a general purpose code for quantum mechanical calculations of molecular properties (Q-Chem) to use a graphical processing unit. We report a 4.3x speedup of the resolution-of-the-identity second-order Møller-Plesset perturbation theory execution time for single point energy calculation of linear alkanes. Furthermore, we obtain the correlation and total energy for n-octane conformers as the torsional angle of central bond is rotated to show that precision is not lost for these types of calculations. This code modification is accomplished using the NVIDIA CUDA Basic Linear Algebra Subprograms (CUBLAS) library for an NVIDIA Quadro FX 5600 graphics card. Finally, we anticipate further speedups of other matrix algebra based electronic structure calculations using a similar approach. (Accelerating Resolution-of-the-Identity Second-Order Møller-Plesset Quantum Chemistry Calculations with Graphical Processing Units. Vogt, L., Olivares-Amaya, R., Kermes, S., Shao, Y., Amador-Bedolla, C., and Aspuru-Guzik, A. J. Phys. Chem. A, 2008, DOI: 10.1021/jp0776762)

Quantum Monte Carlo on GPUs

September 10th, 2007

This paper by Anderson et al at Caltech describes a method to use GPUs to accelerate Quantum Monte Carlo on a GPU. QMC is among the most accurate (and expensive) methods in the quantum chemistry zoo. Primarily, this involves the investigation of tricks available to this algorithm to speed up matrix multiplication. That is, as a statistical algorithm, the authors studied the performance enhancements available when multiplying many matrices simultaneously. Additionally, the paper explores the Kahan Summation Formula to improve the accuracy of GPU matrix multiplication. (Quantum Monte Carlo on Graphical Processing Units. Amos G. Anderson, William A Goddard III, Peter Schroder. Computer Physics Communications)