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

ABSTRACT 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 when running on RTX 4080 SUPER. The package also supports multiple GPUs via MPI, achieving a speedup of with 2 GPUs and approximately 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 .