High-Throughput Characterization of Porous Materials Using Graphics Processing Units.

We have developed a high-throughput graphics processing unit (GPU) code that can characterize a large database of crystalline porous materials. In our algorithm, the GPU is utilized to accelerate energy grid calculations, where the grid values represent interactions (i.e., Lennard-Jones + Coulomb potentials) between gas molecules (i.e., CH4 and CO2) and materials' framework atoms. Using a parallel flood fill central processing unit (CPU) algorithm, inaccessible regions inside the framework structures are identified and blocked, based on their energy profiles. Finally, we compute the Henry coefficients and heats of adsorption through statistical Widom insertion Monte Carlo moves in the domain restricted to the accessible space. The code offers significant speedup over a single core CPU code and allows us to characterize a set of porous materials at least an order of magnitude larger than those considered in earlier studies. For structures selected from such a prescreening algorithm, full adsorption isotherms can be calculated by conducting multiple Grand Canonical Monte Carlo (GCMC) simulations concurrently within the GPU.