Computational Frameworks

iHB-FEM is the in-house computational framework developed by the FLEXOCOMP Group. 

The framework allows the smooth approximation of 2D/3D PDE by means of Cartesian B-spline approximation spaces unfitted to the geometry, hence it is particularly useful for solving high-order PDE.

Although it was originally developed for high-order electromechanical applications -in particular, flexoelectricity- it is extensible and modular, allowing for other multiphysic applications such as semiconductivity, flexo-photovoltaics, and others. It also allows body-fitted B-spline approximations in Cartesian domains.

The Cartesian structure of the approximation space enables the efficient simulation of representative volume elements (RVE) of architected metamaterials by means of generalized-periodic approximation spaces, which inherit the properties of the original B-spline spaces -in particular, its smoothness.

The code is written in Matlab, and it makes use of certain precompiled C libraries and vectorization/parallelization features that result in a good efficiency and reasonable scalability.

SPARC-X is an open source computational framework, developed by the SPARC-X team, for performing Kohn-Sham Density Functional Theory (DFT) calculations that scale linearly with system size, leveraging petascale/exascale parallel computers to study chemical phenomena at length and time scales previously accessible only by empirical approaches — e.g., 100,000 atoms for a few picoseconds using semilocal functionals or 1,000 atoms for a few nanoseconds using hybrid functionals. To do so, SPARC-X will exploit a recent breakthrough in electronic structure methodologies: systematically improvable, strictly local, orthonormal, discontinuous real-space bases that efficiently and systematically capture the local chemistry of the system. With further adaptation using new machine-learning techniques and the use of the massively parallel Spectral Quadrature (SQ) method, the algorithmic complexity and prefactor associated with DFT calculations involving semilocal as well as hybrid functionals will be dramatically reduced.

The capability provided by SPARC-X has applications in a wide variety of chemical sciences, including reactive interfaces where large length- and/or long time-scales are needed and traditional force fields fail. This is particularly important in dynamic catalysis, where bond breaking and formation must be understood in detail. This project will develop, test, and apply the SPARC-X framework to understand the photocatalytic properties of TiO2 systems with and without Au co-catalysts for nitrogen transformations. This integrated development and application strategy will ensure that SPARC-X is a robust, efficient, and scalable software package for quantum simulations on current petascale and future exascale computing resources and enable fully ab initio investigation of key catalytic systems previously beyond reach.