Nexus-NRS (Nuclear Reaction Suite): Open Modern Functional-Programming Software for Nuclear Reaction Modeling with DWBA

Nexus-NRS is an open and reproducible software framework for nuclear reaction calculations, implemented in a functional-programming style (Clojure), with a focus on workflows relevant to halo systems: stable radial solvers for weakly bound states, scattering observables, and transfer reactions. The package includes optical-model potentials, Riccati–Numerov integration with regular near-origin initialization options, discrete Wronskian diagnostics for numerical stability, and a Distorted Wave Born Approximation (DWBA) implementation for single-nucleon transfer in the post form. Recent development extends the reaction layer with multipole/angular ingredients in the spirit of Austern (complex radial integrals for zero-range cluster transitions, Coulomb-barrier phase factors on multipole blocks) and with a literature-aligned benchmark for 11Li(p,p′) inelastic scattering using published global optical parameters. Nexus-NRS supports both scripting/REPL-driven studies and an interactive web dashboard for parameter exploration and visualization; a public instance is deployed at https://www.nexus-nrs.uz, and the dashboard exposes representative benchmarks through JSON endpoints (including angular dσ/dΩ for the 11Li paper workflow). The project plans to support use from an LLM chatbot for guided workflows. This manuscript describes the numerical formulation and software architecture and outlines a validation workflow aimed at producing reproducible conference-scale results.