C++ SGT implementation example

This is a simple C++ example that uses and upward and a downward pass to accumulate / distribute the structure factors. The calculation is parallelized by distributing over the quadrature points for simplicity, with the resulting energies and forces from each core accumulated at the end.

Prerequisites

As noted in the parent directory's notes, we assume that the SS31-Mar-2016 folder has been downloaded and placed one level up from this directory.

Building

This example code uses CMake to build, and will automatically detect OpenMP for parallelism. This code uses special functions from a header-only subset of Boost C++ library, which is bundled as part of this codebase; CMake will automatically set the build up to find these files. To build, run:

mkdir build
cd build
cmake ..
make -j8

If the build ran successfully then, e.g., to run a waterbox using a real space cutoff of 12.0, aiming for 1E-9 precision on 4 cores simply run:

./run_waterbox 9 12.0 4 ../../SS31-Mar-2016 ../Data/waterbox.xyz

The waterbox xyz file follows the Tinker format: another simple utility is provided to build larger waterboxes by translating along the x, y, and/or, z axes.