We develop software tools and database to enable high-quality molecular mechanics (MM) calculations, which covers MM model generation for arbitrary organic molecules and biomolecular building blocks, molecular mechanics force field (MMFF) parameterization, MMFF-based scoring functions, binding free energy calculations using endpoint approaches, target-specific machine-learning (ML)-based modeling, computer-aided drug design (CADD) tools for developing new and repurposing approved drugs for fighting COVID-19.