Syntheseus is a Python package for retrosynthetic planning that provides a unified framework for integrating various single-step reaction models with search algorithms to find synthetic routes from target molecules to available starting materials. The package features a plugin architecture that allows users to plug in different reaction models (such as Chemformer, GLN, LocalRetro, etc.) and search algorithms (like MCTS, Retro*, Breadth-First, etc.) through well-defined abstract base classes. It includes command-line interfaces for running end-to-end searches and evaluating single-step model performance, along with tools for route analysis and visualization. The architecture emphasizes separation of concerns: the interface module defines core abstractions (molecule, reaction, bag, and models), the reaction_prediction module handles model loading and inference, and the search module implements the search algorithms and graph representations. This design enables easy extension and experimentation with new models and algorithms. The package is actively used in academic research and has been applied in recent publications for benchmarking retrosynthesis approaches.
VASPy is a pure Python library for manipulating and analyzing VASP (Vienna Ab initio Simulation Package) input and output files. It provides object-oriented parsers for common VASP formats including POSCAR, CONTCAR, XDATCAR, OUTCAR, OSZICAR, INCAR, DOS, ELFCAR, CHGCAR, and also supports Materials Studio formats (XSD, ARC, XTD). The library exposes high-level classes like PosCar, OutCar, DosX, and InCar that encapsulate file parsing, coordinate transformations, and data extraction, enabling users to programmatically read, modify, and visualize simulation results. It also includes a set of command-line scripts for common tasks such as creating VASP inputs, extracting forces, computing zero-point energies, and converting between file formats. The architecture is modular, with separate modules for atomic coordinates, electronic structure, iterative outputs, and Material Studio interoperability, all built on a shared base class and utility functions. Visualization is a key feature, with matplotlib and PyVista backends for plotting DOS, charge densities, and trajectories. The library is designed for computational materials science researchers and DFT practitioners who need to automate post-processing and workflow tasks around VASP calculations.