Oct 2026· Zenodo (CERN European Organization for Nuclear Research)
Various Chemistry Research Topics
Abstract
This entry presents 4-Chlorobenzotrichloride (C7H4Cl4; CAS 5216-25-1; PubChem CID 21277) as a 3D-printable ball-and-stick model in which every atom carries its engraved element symbol (C, H, Cl), so the model can be read without a colour key. Atomic coordinates come from the PubChem-computed 3D conformer (not an experimental crystal structure); coordinates and connectivity are unchanged. Biological relevance: 4-Chlorobenzotrichloride is recorded as a carcinogen (source: Wikidata Q22338118, retrieved 2026-10-10). Structure at a glance 15 atoms: 7 C, 4 H, 4 Cl 15 bonds: 9 single, 6 aromatic One aromatic 6-membered ring Functional groups: four C-Cl bonds No hydrogen-bond donors or acceptors (computed) Fraction of sp3-hybridised (tetrahedral) carbon atoms: 0.14 (computed) Use in teaching Counting task: students tally the engraved symbols (7 C, 4 H, 4 Cl; 15 atoms) and rebuild the formula C7H4Cl4 from the model alone. Aromaticity: identify the aromatic ring and the 6 bonds recorded as aromatic. Functional groups: find the four C-Cl bonds on the model and name each one. File and printing STL mesh of 226,358 triangles, a closed (watertight) single solid. Coordinates are in ångström and STL stores no unit, so scale the model deliberately in your slicer. Measured bounding box: 6.764 × 6.25 × 4.526 Å; at scale factor 10 (1 Å to 10 mm, file read in millimetres) the print measures about 67.6 × 62.5 × 45.3 mm. SHA-256: 97bedc6618b22975f18e30238734cd8e219a99bcd8342f490daf03713a4d7ef1. Validation InChIKey identical to the PubChem record (PubChem FTP SDF, file dated 2026-10-08): LVZPKYYPPLUECL-UHFFFAOYSA-N Molecular formula and hydrogen-bond donor/acceptor counts identical to PubChem Mesh: triangle count in the header equals the actual count; 0 edges not shared by exactly two triangles; 1 connected solid; SHA-256 equal to the published file Source, licence and identifiers Full record: molgod.org/molecule/5216-25-1 · Licence and provenance record: molgod.org/licenses/stl/5216-25-1 · Same file on Wikimedia Commons: File:4-Chlorobenzotrichloride-3D-molecular-model-engraved-CAS-5216-25-1.stl MolGod ID: MG_191-835-326-67 Wikidata: Q22338118 EC number: 226-009-1 ChemSpider ID: 20002 IUPAC name: 1-chloro-4-(trichloromethyl)benzene InChIKey: LVZPKYYPPLUECL-UHFFFAOYSA-N SMILES: C1=CC(=CC=C1C(Cl)(Cl)Cl)Cl Molar mass 229.9 g/mol (exact mass 229.903761) Licence: CC BY-SA 4.0 (licence text). Required attribution: "4-Chlorobenzotrichloride 3D model by MolGod.org — https://molgod.org/molecule/5216-25-1/ — CC BY-SA 4.0".
This publication proposes a definition and a classification of agile software development approaches and analyses ten software development methods that can be characterized as being "agile" against the defined criterion.
P. Abrahamsson, O. Salo, Jussi Ronkainen et al.· arXiv.org· 727 citations· ⚡54
The study shows that agile practices improve both informal and formal communication, but indicates that, in larger development situations involving multiple external stakeholders, a mismatch of adequate communication mechanisms can sometimes even hinder the communication.
M. Pikkarainen, Jukka Haikara, O. Salo et al.· Empirical Software Engineeri...· 401 citations· ⚡48
The results indicate that software engineering work practices are chosen opportunistically, adapted and configured to provide value under the constrains imposed by the startup context.
Nicolò Paternoster, Carmine Giardino, M. Unterkalmsteiner et al.· Information and Software Tec...· 394 citations· ⚡54
The perception of the impact of agile methods is predominantly positive, and several challenge areas were discovered, but based on this study, agile methods are here to stay.
M. Laanti, O. Salo, P. Abrahamsson· Information and Software Tec...· 260 citations· ⚡20
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