{"record_type":"pith_number_record","schema_url":"https://pith.science/schemas/pith-number/v1.json","pith_number":"pith:2026:3YQQGOM56ZUIMTTZLRQEYBLI6S","short_pith_number":"pith:3YQQGOM5","schema_version":"1.0","canonical_sha256":"de2103399df668864e795c604c0568f4aa1354ffca805fc9039c5b3493311e41","source":{"kind":"arxiv","id":"2607.12202","version":1},"attestation_state":"computed","paper":{"title":"Defect assignment of the clock site in $^{229}\\text{Th:CaF}_2$","license":"http://creativecommons.org/licenses/by/4.0/","headline":"","cross_cats":[],"primary_cat":"physics.atom-ph","authors_text":"Andrei Derevianko, Daniel A. Rehn, Eric R. Hudson, Harris E. Mason, Harry W. T. Morgan, H. B. Tran Tan, Igor M. Savukov, Michael J. Martin, Ricky Elwell","submitted_at":"2026-07-13T23:10:04Z","abstract_excerpt":"The performance of solid-state $^{229}\\text{Th}$ nuclear clocks depends sensitively on the microscopic environment of the thorium nucleus in the host crystal. Here we reassess the dominant quadrupole-split thorium site in $^{229}\\text{Th:CaF}_2$, which has been assigned to a thorium dimer in recent spectroscopic work. Thermodynamic estimates, density functional theory calculations, and electric-field-gradient comparisons instead favor an isolated $\\text{Th}^{4+}$ substitution on a $\\text{Ca}^{2+}$ site charge-compensated by two nearby fluorine interstitials in a relaxed $90^\\circ$ motif. The s"},"verification_status":{"content_addressed":true,"pith_receipt":true,"author_attested":false,"weak_author_claims":0,"strong_author_claims":0,"externally_anchored":false,"storage_verified":false,"citation_signatures":0,"replication_records":0,"graph_snapshot":true,"references_resolved":false,"formal_links_present":false},"canonical_record":{"source":{"id":"2607.12202","kind":"arxiv","version":1},"metadata":{"license":"http://creativecommons.org/licenses/by/4.0/","primary_cat":"physics.atom-ph","submitted_at":"2026-07-13T23:10:04Z","cross_cats_sorted":[],"title_canon_sha256":"29f37ea2b83cb5c4431e335c9dffd6f52f427a8168b3b4239d1cc9e2b5c8a821","abstract_canon_sha256":"6a5a6c0bfc14705e6c5c7b6cf45fb6156df27f5352ed0bf36548f34fee781eca"},"schema_version":"1.0"},"receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-07-15T00:21:38.372086Z","signature_b64":"K/R0FT0/6PKRq1Qy4YAt3+Wqvt3QRn0K3Kexip5EF1BwWX4+Srps0rmlvzfJH8XywrvZH0K/UnmJGUp8oMcKBg==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"de2103399df668864e795c604c0568f4aa1354ffca805fc9039c5b3493311e41","last_reissued_at":"2026-07-15T00:21:38.371220Z","signature_status":"signed_v1","first_computed_at":"2026-07-15T00:21:38.371220Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"graph_snapshot":{"paper":{"title":"Defect assignment of the clock site in $^{229}\\text{Th:CaF}_2$","license":"http://creativecommons.org/licenses/by/4.0/","headline":"","cross_cats":[],"primary_cat":"physics.atom-ph","authors_text":"Andrei Derevianko, Daniel A. Rehn, Eric R. Hudson, Harris E. Mason, Harry W. T. Morgan, H. B. Tran Tan, Igor M. Savukov, Michael J. Martin, Ricky Elwell","submitted_at":"2026-07-13T23:10:04Z","abstract_excerpt":"The performance of solid-state $^{229}\\text{Th}$ nuclear clocks depends sensitively on the microscopic environment of the thorium nucleus in the host crystal. Here we reassess the dominant quadrupole-split thorium site in $^{229}\\text{Th:CaF}_2$, which has been assigned to a thorium dimer in recent spectroscopic work. Thermodynamic estimates, density functional theory calculations, and electric-field-gradient comparisons instead favor an isolated $\\text{Th}^{4+}$ substitution on a $\\text{Ca}^{2+}$ site charge-compensated by two nearby fluorine interstitials in a relaxed $90^\\circ$ motif. The s"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"2607.12202","kind":"arxiv","version":1},"verdict":{"id":null,"model_set":{},"created_at":null,"strongest_claim":"","one_line_summary":"","pipeline_version":null,"weakest_assumption":"","pith_extraction_headline":""},"integrity":{"clean":true,"summary":{"advisory":0,"critical":0,"by_detector":{},"informational":0},"endpoint":"/pith/2607.12202/integrity.json","findings":[],"available":true,"detectors_run":[],"snapshot_sha256":"c28c3603d3b5d939e8dc4c7e95fa8dfce3d595e45f758748cecf8e644a296938"},"references":{"count":0,"sample":[],"resolved_work":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57","internal_anchors":0},"formal_canon":{"evidence_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"author_claims":{"count":0,"strong_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"builder_version":"pith-number-builder-2026-05-17-v1"},"aliases":[{"alias_kind":"arxiv","alias_value":"2607.12202","created_at":"2026-07-15T00:21:38.371670+00:00"},{"alias_kind":"arxiv_version","alias_value":"2607.12202v1","created_at":"2026-07-15T00:21:38.371670+00:00"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.2607.12202","created_at":"2026-07-15T00:21:38.371670+00:00"},{"alias_kind":"pith_short_12","alias_value":"3YQQGOM56ZUI","created_at":"2026-07-15T00:21:38.371670+00:00"},{"alias_kind":"pith_short_16","alias_value":"3YQQGOM56ZUIMTTZ","created_at":"2026-07-15T00:21:38.371670+00:00"},{"alias_kind":"pith_short_8","alias_value":"3YQQGOM5","created_at":"2026-07-15T00:21:38.371670+00:00"}],"events":[],"event_summary":{},"paper_claims":[],"inbound_citations":{"count":0,"internal_anchor_count":0,"sample":[]},"formal_canon":{"evidence_count":0,"sample":[],"anchors":[]},"links":{"html":"https://pith.science/pith/3YQQGOM56ZUIMTTZLRQEYBLI6S","json":"https://pith.science/pith/3YQQGOM56ZUIMTTZLRQEYBLI6S.json","graph_json":"https://pith.science/api/pith-number/3YQQGOM56ZUIMTTZLRQEYBLI6S/graph.json","events_json":"https://pith.science/api/pith-number/3YQQGOM56ZUIMTTZLRQEYBLI6S/events.json","paper":"https://pith.science/paper/3YQQGOM5"},"agent_actions":{"view_html":"https://pith.science/pith/3YQQGOM56ZUIMTTZLRQEYBLI6S","download_json":"https://pith.science/pith/3YQQGOM56ZUIMTTZLRQEYBLI6S.json","view_paper":"https://pith.science/paper/3YQQGOM5","resolve_alias":"https://pith.science/api/pith-number/resolve?arxiv=2607.12202&json=true","fetch_graph":"https://pith.science/api/pith-number/3YQQGOM56ZUIMTTZLRQEYBLI6S/graph.json","fetch_events":"https://pith.science/api/pith-number/3YQQGOM56ZUIMTTZLRQEYBLI6S/events.json","actions":{"anchor_timestamp":"https://pith.science/pith/3YQQGOM56ZUIMTTZLRQEYBLI6S/action/timestamp_anchor","attest_storage":"https://pith.science/pith/3YQQGOM56ZUIMTTZLRQEYBLI6S/action/storage_attestation","attest_author":"https://pith.science/pith/3YQQGOM56ZUIMTTZLRQEYBLI6S/action/author_attestation","sign_citation":"https://pith.science/pith/3YQQGOM56ZUIMTTZLRQEYBLI6S/action/citation_signature","submit_replication":"https://pith.science/pith/3YQQGOM56ZUIMTTZLRQEYBLI6S/action/replication_record"}},"created_at":"2026-07-15T00:21:38.371670+00:00","updated_at":"2026-07-15T00:21:38.371670+00:00"}