We have used OpenAtom to understand and model the materials that are used for
hydrogen storage application, which is one of the major goals of today's
science and technology research. In this project we try to showcase the
diverse functionality as well as scalability of OpenAtom via performance and
scientific case studies. In particular, we focus on a metal organic framework
(MOF) with application to hydrogen storage that consists of 424 atoms (Figure
1) and 936 electronic states, and requires 0.8 billion plane wave expansion
coefficients to describe. The main goal of this project is to understand
hydrogen diffusion in MOF system at finite temperature as for practical
hydrogen storage media, the kinetic properties of hydrogen are very important
together with high hydrogen uptake capacity. To investigate the kinetic
properties such as diffusion of H2 in MOFs, CPAIMD simulation is appropriate.
In addition, path integral based CPAIMD can treat nuclear quantum effects,
which can acurately describe the diffusion process.
We have generated preliminary work on hydrogen diffusion in MOF-Zn using a
proper description of van der Waals interaction via the DFT-D2 method of
Grimme. Figure 2 and 3 bove depict mean square displacement of the hydrogen atoms
inside the MOF at two different temperatures. Movie on the upper right shows how H2 molecules
(in white balls) move inside MOF.