ERmod-OpenACC: GPU Acceleration of Solvation Free Energy Calculation With Energy-Representation Theory.

ERmod-OpenACC is a GPU-accelerated implementation of a calculation package for the solvation free energy. In the implementation, the most computationally intensive processes-the calculation of the pair energies and the construction of the correlation function-have been optimized for GPUs. ERmod-OpenACC also supports single precision to maximize performance on RTX series GPUs, which are commonly used in molecular dynamics simulations. A common problem with OpenACC is data transfer between the CPU and GPU. By minimizing data transfer, the package's performance has been significantly improved. Compared to a single Xeon core (3.1 GHz), ERmod-OpenACC achieves a speedup of up to approximately 16 . 5 × $$ 16.5\times $$ when running on RTX 4080 SUPER. The package also supports multiple GPUs via MPI, achieving a speedup of 2 × $$ 2\times $$ with 2 GPUs and approximately 14 . 5 × $$ 14.5\times $$ with 16 GPUs. The only external library required to compile ERmod-ACC is NVIDIA HPC SDK. The package is available at https://github.com/drmaruyama/ermod-openacc.