Worked on enhancing the stability and reliability of core numerical routines in the deepmodeling/abacus-develop repository, focusing on C++ development. Addressed a critical bug in the SplineD2 function by initializing multiple variables to default values, which prevented undefined behavior during calculations and improved determinism in simulation results. The technical approach involved careful analysis of initialization gaps and collaborative implementation of robust default value assignments. This work contributed to more predictable and stable numerical computations within the codebase. The developer applied expertise in C++ and numerical methods, emphasizing code safety and reliability over new feature development during the reported period.