Glossary

BVS. Bond Valence Sum. An empirical method in crystallography and coordination chemistry used to estimate the oxidation states of atoms based on observed bond lengths. shapeXT supports numerical approaches by Brown (1985) and O'Keeffe (1991), as well as calculations utilizing tabulated reference parameters (as provided on the IUCr website).

CShM. Continuous Shape Measures. A quantitative approach used in coordination chemistry to evaluate the degree of distortion of a molecule's coordination sphere relative to an ideal reference polyhedron (such as a perfect tetrahedron or octahedron). A CShM value of zero indicates a perfect match to the ideal shape. shapeXT provides an integrated tool to calculate and analyze these measures interactively.

COD. Crystallography Open Database. An open-access collection of crystal structures of organic, inorganic, metal-organic compounds, and minerals. shapeXT allows users to fetch and visualize structures directly from this database using a 7-digit ID.

GPU. Graphics processing unit.

MoltenVK. A software translation layer that maps Vulkan API calls to Apple's Metal graphics framework. shapeXT relies on MoltenVK to bring its Vulkan renderer seamlessly to macOS and Apple Silicon hardware.

SPIR-V. SPIR-V™ is a registered trademark of the Khronos Group Inc.

VSA. Visible Solid Angle. A metric used to quantify the steric accessibility of a metal binding site and its capacity to accommodate additional ligands. By evaluating the open space around a central atom, this approach helps predict crossover points for coordination (e.g., binding in complex cations). shapeXT features integrated visible solid angle calculation and visualization.

Vulkan. Vulkan® is a new-generation graphics and compute API for high-efficiency, cross-platform access to GPUs. Vulkan and the Vulkan logo are registered trademarks of the Khronos Group Inc.