Even lattices of rank 20 and determinant 5

Complete list here (see the main page for format details).

• 27 isometry classes, mass 45253546977779599/13560598743968856932352000000.
• 27 possible root systems, see here for statistics of reduced masses for each root system.
• Isometry classes distinguished by invariant: root system.
• Classified in: G. Chenevier & O. Taïbi, Unimodular lattices of rank 29 and related even genera of small determinant, arXiv preprint (2026).
• Construction(s): Exceptional vectors in rank 21 unimodular lattices (unique orbit). Norm 5/6 vectors in duals of rank 21 even lattices of determinant 6. Norm 5/14 vectors in duals of rank 21 even lattices of determinant 14. Embeddings of \({\rm A}_4\) in Niemeier lattices.