#materials-science

X-ray crystallography maths as an API, computed locally and deterministically. The angle endpoint applies Bragg’s law, n·λ = 2·d·sinθ, to give the diffraction angle θ and the experimentally plotted 2θ from a crystal’s inter-planar spacing and the X-ray wavelength, defaulting to the common Cu Kα source at 0.15406 nm and reporting the highest observable order ⌊2d/λ⌋ — a 0.2 nm plane spacing diffracts Cu Kα to θ ≈ 22.65°, a 2θ peak near 45.3°. The spacing endpoint inverts the law, d = n·λ/(2·sinθ), reading the lattice spacing straight off a measured XRD peak — the everyday job of indexing a diffraction pattern, so a 2θ of 31.77° for table salt gives the 0.2814 nm (200) spacing. The wavelength endpoint solves λ = 2·d·sinθ/n to identify or calibrate the source. Lengths are entered in nanometres or ångström and angles in degrees, and any diffraction order n is supported. Everything is computed locally and deterministically, so it is instant and private. Ideal for materials-science, crystallography, mineralogy, XRD, semiconductor and solid-state-physics app developers, lattice-spacing and pattern-indexing tools, and laboratory software. Pure local computation — no key, no third-party service, instant. Live, nothing stored. 3 endpoints. This is reflection-geometry Bragg diffraction with the 2d factor; for optical double-slit and grating diffraction use a wave-optics diffraction API.

api.oanor.com/bragg-api

Isotropic elastic-constant mechanics as an API, computed locally and deterministically. The convert endpoint takes any two of the five linear-elastic constants — Young’s modulus E, shear modulus G, bulk modulus K, Poisson’s ratio ν and the first Lamé parameter λ — and returns all five, using the standard isotropic relations (G = E/(2(1+ν)), K = E/(3(1−2ν)), λ = Eν/((1+ν)(1−2ν)) and their inversions for the pairs E+ν, G+ν, K+ν, E+G, E+K, K+G, G+λ, K+λ and λ+ν); steel given E = 200 GPa and ν = 0.3 comes back as G ≈ 76.92 GPa, K ≈ 166.67 GPa and λ ≈ 115.38 GPa. The wave-speeds endpoint computes the longitudinal (P) and shear (S) elastic wave speeds from two moduli and the density, vp = √((K + 4G/3)/ρ) and vs = √(G/ρ), together with the vp/vs ratio used in seismology and ultrasonic testing — steel comes out at about 5860 m/s for P-waves and 3130 m/s for S-waves. Moduli convert in whatever consistent unit you supply (the wave-speed endpoint expects strict SI: pascals and kg/m³ for metres per second). Everything is computed locally and deterministically, so it is instant and private. Ideal for materials-science, mechanical-engineering, geophysics, seismology, ultrasonic-NDT and FEA app developers, material-property and rock-physics tools, and simulation software. Pure local computation — no key, no third-party service, instant. Live, nothing stored. 2 endpoints. This interconverts elastic constants; for Young’s modulus from a stress/strain tensile test use a Young’s-modulus API.

api.oanor.com/elasticmoduli-api

Crystal structures as an API — powered by the Crystallography Open Database (COD), the open, public-domain collection of over 500,000 crystal structures of organic, inorganic, metal-organic compounds and minerals. Search the database by chemical formula (any standard casing — TiO2, Al2O3, H2O — is normalised automatically) or by free text over mineral names, titles and comments, then look up any structure to get its full crystallographic data: chemical and cell formula, space group (Hermann-Mauguin and Hall), the complete unit cell (a, b, c, alpha, beta, gamma and volume), the source publication (title, authors, journal, year, DOI) and a link to the CIF file. From quartz, calcite and diamond to anatase, corundum and diopside, it is ideal for materials science, solid-state chemistry, mineralogy, crystallography teaching and research tooling. This is a crystal-structure & materials database — distinct from molecule-property (chemistry / PubChem) and protein-structure (PDB) databases. Open data from the Crystallography Open Database (CC0 / public domain).

api.oanor.com/cod-api