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How the science is checked§

Every computational model behind a figure is tested twice: by its author against worked examples, and by an independent test suite written from the published equations and reference values, without reading the model's code. Every factual claim is recorded in a claims register with its source and checked by a reviewer who did not write it. What each figure simplifies is stated next to the figure.

What is computed and what is measured§

The arrangements of electron domains are computed: the figures let points on a sphere repel each other until they settle, and the engine's tests check the result against the exact polyhedra. Lewis structures are built by the five-step textbook procedure for a checked list of molecules and ions, not for arbitrary formulas. Bond angles and dipole moments shown as "measured" are experimental gas-phase values from the NIST Computational Chemistry Comparison and Benchmark Database; boiling points come from the NIST Chemistry WebBook; electronegativities are Pauling-scale values from PubChem. The figures never present a model number as a measurement: where the simple models fail (the size of the lone-pair squeeze, the ranking of the chloromethanes' dipoles, ozone), the pages say so.

Found an error?§

Please open an issue on the source repository. Corrections are welcome and are credited.

Reuse§

Text and figures are licensed CC BY 4.0; code is MIT. Teachers may use and adapt any of it, with attribution.