{"paper":{"title":"Open-shell Tensor Hypercontraction","license":"","headline":"Open-shell LS-THC-MP2 and MP3 recover closed-shell accuracy for radicals and bond-breaking without extra spin corrections.","cross_cats":[],"primary_cat":"physics.chem-ph","authors_text":"Devin A. Matthews, Megan Simons, Tingting Zhao","submitted_at":"2023-04-08T15:16:49Z","abstract_excerpt":"The extension of least-squares tensor hypercontracted second- and third-order Møller-Plessett perturbation theory (LS-THC-MP2 and LS-THC-MP3) to open-shell systems is an important development due to the scaling reduction afforded by THC and the ubiquity of molecular ions, radicals, and other open-shell reactive species. The complexity of wavefunction-based quantum chemical methods such as Møller-Plessett and coupled cluster theory is reflected in the steep scaling of the computational costs with the molecular size. The least-squares tensor hypercontraction (LS-THC) method is an efficient, sing"},"claims":{"count":4,"items":[{"kind":"strongest_claim","text":"Open-shell LS-THC-MP n methods exhibit errors highly comparable to those produced by closed-shell LS-THC-MP n, and are highly insensitive to particular chemical interactions, geometries, or even to moderate spin contamination.","source":"verdict.strongest_claim","status":"machine_extracted","claim_id":"C1","attestation":"unclaimed"},{"kind":"weakest_assumption","text":"The assumption that diagrammatic spin summation and least-squares fitting of the amplitude tensor will preserve accuracy for open-shell cases without additional spin-specific corrections or re-optimization of THC factors.","source":"verdict.weakest_assumption","status":"machine_extracted","claim_id":"C2","attestation":"unclaimed"},{"kind":"one_line_summary","text":"Open-shell LS-THC-MP2 and MP3 deliver scaling reductions with accuracy comparable to closed-shell versions and low sensitivity to geometry or spin contamination.","source":"verdict.one_line_summary","status":"machine_extracted","claim_id":"C3","attestation":"unclaimed"},{"kind":"headline","text":"Open-shell LS-THC-MP2 and MP3 recover closed-shell accuracy for radicals and bond-breaking without extra spin corrections.","source":"verdict.pith_extraction.headline","status":"machine_extracted","claim_id":"C4","attestation":"unclaimed"}],"snapshot_sha256":"0f391edeb34c760ae1573346fe877856e099031fd6194e4df58788e3fae696ab"},"source":{"id":"2304.04040","kind":"arxiv","version":2},"verdict":{"id":"3e9a8ab6-5476-45dd-9f42-a229d20d4588","model_set":{"reader":"grok-4.3"},"created_at":"2026-05-14T22:00:09.486907Z","strongest_claim":"Open-shell LS-THC-MP n methods exhibit errors highly comparable to those produced by closed-shell LS-THC-MP n, and are highly insensitive to particular chemical interactions, geometries, or even to moderate spin contamination.","one_line_summary":"Open-shell LS-THC-MP2 and MP3 deliver scaling reductions with accuracy comparable to closed-shell versions and low sensitivity to geometry or spin contamination.","pipeline_version":"pith-pipeline@v0.9.0","weakest_assumption":"The assumption that diagrammatic spin summation and least-squares fitting of the amplitude tensor will preserve accuracy for open-shell cases without additional spin-specific corrections or re-optimization of THC factors.","pith_extraction_headline":"Open-shell LS-THC-MP2 and MP3 recover closed-shell accuracy for radicals and bond-breaking without extra spin corrections."},"references":{"count":0,"sample":[],"resolved_work":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57","internal_anchors":0},"formal_canon":{"evidence_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"author_claims":{"count":1,"strong_count":1,"snapshot_sha256":"5e3b23b793a24ad44d50f012bed3c12f7c9e9c566d826ad85b79440943422c6c"},"builder_version":"pith-number-builder-2026-05-17-v1"}