{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2010:QU6YA35G6ZENBLKXGP2W5SGGMI","merge_version":"pith-open-graph-merge-v1","event_count":2,"valid_event_count":2,"invalid_event_count":0,"equivocation_count":0,"current":{"canonical_record":{"metadata":{"abstract_canon_sha256":"521a503e3a958a3cd3a054547f52a2ba49b843cc46e24a2f282b3e97d2937639","cross_cats_sorted":["physics.chem-ph"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cond-mat.mtrl-sci","submitted_at":"2010-07-15T13:58:11Z","title_canon_sha256":"73d4f1e6564928252352651b1002afe1264eed40fddcc7d81f6443d056e0d164"},"schema_version":"1.0","source":{"id":"1007.2563","kind":"arxiv","version":1}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1007.2563","created_at":"2026-05-18T04:42:22Z"},{"alias_kind":"arxiv_version","alias_value":"1007.2563v1","created_at":"2026-05-18T04:42:22Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1007.2563","created_at":"2026-05-18T04:42:22Z"},{"alias_kind":"pith_short_12","alias_value":"QU6YA35G6ZEN","created_at":"2026-05-18T12:26:13Z"},{"alias_kind":"pith_short_16","alias_value":"QU6YA35G6ZENBLKX","created_at":"2026-05-18T12:26:13Z"},{"alias_kind":"pith_short_8","alias_value":"QU6YA35G","created_at":"2026-05-18T12:26:13Z"}],"graph_snapshots":[{"event_id":"sha256:3138cd8b7d6b26a9d4c403bce7fc1c3c570e3ba2a76d0e41dc7426299b2f0eaf","target":"graph","created_at":"2026-05-18T04:42:22Z","signer":{"key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signer_id":"pith.science","signer_type":"pith_registry"},"payload":{"graph_snapshot":{"author_claims":{"count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57","strong_count":0},"builder_version":"pith-number-builder-2026-05-17-v1","claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"formal_canon":{"evidence_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"paper":{"abstract_excerpt":"We investigate the binding of single and quadruple hydrogen molecules on a positively charged Ca ion. By comparing with benchmark quantum Monte Carlo (QMC) calculations we demonstrate wide variability in other more approximate electronic structure methods including common density functionals. Single determinant QMC calculations find no binding at short range by approximately 0.1 eV for the quadruple hydrogen molecule case, for a fixed hydrogen bond length of 0.77 Angstrom. Density functional calculations using common functionals such a LDA and B3LYP differ substantially from the QMC binding cu","authors_text":"Fernando A. Reboredo, Michal Bajdich, P. R. C. Kent","cross_cats":["physics.chem-ph"],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cond-mat.mtrl-sci","submitted_at":"2010-07-15T13:58:11Z","title":"Quantum Monte Carlo Calculations of Dihydrogen Binding Energetics on Ca Cations: an Assessment of Errors in Density Functionals for Weakly Bonded Systems"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1007.2563","kind":"arxiv","version":1},"verdict":{"created_at":null,"id":null,"model_set":{},"one_line_summary":"","pipeline_version":null,"pith_extraction_headline":"","strongest_claim":"","weakest_assumption":""}},"verdict_id":null}}],"author_attestations":[],"timestamp_anchors":[],"storage_attestations":[],"citation_signatures":[],"replication_records":[],"corrections":[],"mirror_hints":[],"record_created":{"event_id":"sha256:a616003110d6ac197327c17a2b639987f402d56ddae156182fa8268beee45743","target":"record","created_at":"2026-05-18T04:42:22Z","signer":{"key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signer_id":"pith.science","signer_type":"pith_registry"},"payload":{"attestation_state":"computed","canonical_record":{"metadata":{"abstract_canon_sha256":"521a503e3a958a3cd3a054547f52a2ba49b843cc46e24a2f282b3e97d2937639","cross_cats_sorted":["physics.chem-ph"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cond-mat.mtrl-sci","submitted_at":"2010-07-15T13:58:11Z","title_canon_sha256":"73d4f1e6564928252352651b1002afe1264eed40fddcc7d81f6443d056e0d164"},"schema_version":"1.0","source":{"id":"1007.2563","kind":"arxiv","version":1}},"canonical_sha256":"853d806fa6f648d0ad5733f56ec8c6620f229b956f60bd3b198237e197e58bdd","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"853d806fa6f648d0ad5733f56ec8c6620f229b956f60bd3b198237e197e58bdd","first_computed_at":"2026-05-18T04:42:22.979811Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-05-18T04:42:22.979811Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"9bHPdK7BytBBNlt9/TWY64TqVWhretg37rTc7AZsl60LEYFA5cH07LezglZoF3khqYNFTr5DG3N3UziJ6y4qBQ==","signature_status":"signed_v1","signed_at":"2026-05-18T04:42:22.980423Z","signed_message":"canonical_sha256_bytes"},"source_id":"1007.2563","source_kind":"arxiv","source_version":1}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:a616003110d6ac197327c17a2b639987f402d56ddae156182fa8268beee45743","sha256:3138cd8b7d6b26a9d4c403bce7fc1c3c570e3ba2a76d0e41dc7426299b2f0eaf"],"state_sha256":"2114c1dd26f63ae6ee8532496354c3394e8bf453c8442d987e2edafc1958a7ca"}