{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2020:OQVTQYIQIUMH7CBOJT3XVWHZ5K","short_pith_number":"pith:OQVTQYIQ","canonical_record":{"source":{"id":"2007.00476","kind":"arxiv","version":2},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cond-mat.mtrl-sci","submitted_at":"2020-07-01T13:31:38Z","cross_cats_sorted":["cond-mat.other"],"title_canon_sha256":"bfd025e664c9fc578c1b26ac9094ce01a53a393e46ff28e961ddb6a4ecfa97fd","abstract_canon_sha256":"44c3a6636fdaa1bb26b9bbada0a43ebae54a292017f1c5aedff5fc5a84681999"},"schema_version":"1.0"},"canonical_sha256":"742b38611045187f882e4cf77ad8f9ea8d5f39ee2605de91f6277145a62924d9","source":{"kind":"arxiv","id":"2007.00476","version":2},"source_aliases":[{"alias_kind":"arxiv","alias_value":"2007.00476","created_at":"2026-07-05T02:01:30Z"},{"alias_kind":"arxiv_version","alias_value":"2007.00476v2","created_at":"2026-07-05T02:01:30Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.2007.00476","created_at":"2026-07-05T02:01:30Z"},{"alias_kind":"pith_short_12","alias_value":"OQVTQYIQIUMH","created_at":"2026-07-05T02:01:30Z"},{"alias_kind":"pith_short_16","alias_value":"OQVTQYIQIUMH7CBO","created_at":"2026-07-05T02:01:30Z"},{"alias_kind":"pith_short_8","alias_value":"OQVTQYIQ","created_at":"2026-07-05T02:01:30Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2020:OQVTQYIQIUMH7CBOJT3XVWHZ5K","target":"record","payload":{"canonical_record":{"source":{"id":"2007.00476","kind":"arxiv","version":2},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cond-mat.mtrl-sci","submitted_at":"2020-07-01T13:31:38Z","cross_cats_sorted":["cond-mat.other"],"title_canon_sha256":"bfd025e664c9fc578c1b26ac9094ce01a53a393e46ff28e961ddb6a4ecfa97fd","abstract_canon_sha256":"44c3a6636fdaa1bb26b9bbada0a43ebae54a292017f1c5aedff5fc5a84681999"},"schema_version":"1.0"},"canonical_sha256":"742b38611045187f882e4cf77ad8f9ea8d5f39ee2605de91f6277145a62924d9","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-07-05T02:01:30.693125Z","signature_b64":"bg/vcRvvpUF96sUnrXwg/jxuRxkvc+uf5is39xjKuR6DbwPjohL8M66dR3YNQXpO1Bc8nbKRMBprrksJCoSqCQ==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"742b38611045187f882e4cf77ad8f9ea8d5f39ee2605de91f6277145a62924d9","last_reissued_at":"2026-07-05T02:01:30.692636Z","signature_status":"signed_v1","first_computed_at":"2026-07-05T02:01:30.692636Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"2007.00476","source_version":2,"attestation_state":"computed"},"signer":{"signer_id":"pith.science","signer_type":"pith_registry","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"created_at":"2026-07-05T02:01:30Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"bKq7zsD3EjWs+DWeUOhswT7/WpmrAY9i+6xvV9LKdFPNyEsHDBOOfzFmIWEqGl44Yz4BWvbVytm6uCQA12oLBQ==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-08-05T11:15:24.928148Z"},"content_sha256":"fa4967d451725fc69e1711d3915576e8a9106f8dbd9cb7505ea31f18abd42cbb","schema_version":"1.0","event_id":"sha256:fa4967d451725fc69e1711d3915576e8a9106f8dbd9cb7505ea31f18abd42cbb"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2020:OQVTQYIQIUMH7CBOJT3XVWHZ5K","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"Absence of diagonal force constants in cubic Coulomb crystals","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":["cond-mat.other"],"primary_cat":"cond-mat.mtrl-sci","authors_text":"Bartholomew Andrews, Gareth Conduit","submitted_at":"2020-07-01T13:31:38Z","abstract_excerpt":"The quasi-harmonic model proposes that a crystal can be modeled as atoms connected by springs. We demonstrate how this viewpoint can be misleading: a simple application of Gauss' law shows that the ion-ion potential for a cubic Coulomb system can have no diagonal harmonic contribution and so cannot necessarily be modeled by springs. We investigate the repercussions of this observation by examining three illustrative regimes: the bare ionic, density tight-binding, and density nearly-free electron models. For the bare ionic model, we demonstrate the zero elements in the force constants matrix an"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"2007.00476","kind":"arxiv","version":2},"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/2007.00476/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"},"verdict_id":null},"signer":{"signer_id":"pith.science","signer_type":"pith_registry","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"created_at":"2026-07-05T02:01:30Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"Hu3eBJO6BPRBV+lX64wOzJOuZmoXW3MhFtkkvdl2IoZ/RN/zUoF7fPSLPmDzByxQ1ktWmvXJIe9LV3WcTd+CAg==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-08-05T11:15:24.929071Z"},"content_sha256":"45b3d63e1b994b32846a0f4c470e2f7e08a08f8e440ef003a34a873a01906852","schema_version":"1.0","event_id":"sha256:45b3d63e1b994b32846a0f4c470e2f7e08a08f8e440ef003a34a873a01906852"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/OQVTQYIQIUMH7CBOJT3XVWHZ5K/bundle.json","state_url":"https://pith.science/pith/OQVTQYIQIUMH7CBOJT3XVWHZ5K/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/OQVTQYIQIUMH7CBOJT3XVWHZ5K/bundle.json","status":"primary"}],"public_keys":[{"key_id":"pith-v1-2026-05","algorithm":"ed25519","format":"raw","public_key_b64":"stVStoiQhXFxp4s2pdzPNoqVNBMojDU/fJ2db5S3CbM=","public_key_hex":"b2d552b68890857171a78b36a5dccf368a953413288c353f7c9d9d6f94b709b3","fingerprint_sha256_b32_first128bits":"RVFV5Z2OI2J3ZUO7ERDEBCYNKS","fingerprint_sha256_hex":"8d4b5ee74e4693bcd1df2446408b0d54","rotates_at":null,"url":"https://pith.science/pith-signing-key.json","notes":"Pith uses this Ed25519 key to sign canonical record SHA-256 digests. Verify with: ed25519_verify(public_key, message=canonical_sha256_bytes, signature=base64decode(signature_b64))."}],"merge_version":"pith-open-graph-merge-v1","built_at":"2026-08-05T11:15:24Z","links":{"resolver":"https://pith.science/pith/OQVTQYIQIUMH7CBOJT3XVWHZ5K","bundle":"https://pith.science/pith/OQVTQYIQIUMH7CBOJT3XVWHZ5K/bundle.json","state":"https://pith.science/pith/OQVTQYIQIUMH7CBOJT3XVWHZ5K/state.json","well_known_bundle":"https://pith.science/.well-known/pith/OQVTQYIQIUMH7CBOJT3XVWHZ5K/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2020:OQVTQYIQIUMH7CBOJT3XVWHZ5K","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":"44c3a6636fdaa1bb26b9bbada0a43ebae54a292017f1c5aedff5fc5a84681999","cross_cats_sorted":["cond-mat.other"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cond-mat.mtrl-sci","submitted_at":"2020-07-01T13:31:38Z","title_canon_sha256":"bfd025e664c9fc578c1b26ac9094ce01a53a393e46ff28e961ddb6a4ecfa97fd"},"schema_version":"1.0","source":{"id":"2007.00476","kind":"arxiv","version":2}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"2007.00476","created_at":"2026-07-05T02:01:30Z"},{"alias_kind":"arxiv_version","alias_value":"2007.00476v2","created_at":"2026-07-05T02:01:30Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.2007.00476","created_at":"2026-07-05T02:01:30Z"},{"alias_kind":"pith_short_12","alias_value":"OQVTQYIQIUMH","created_at":"2026-07-05T02:01:30Z"},{"alias_kind":"pith_short_16","alias_value":"OQVTQYIQIUMH7CBO","created_at":"2026-07-05T02:01:30Z"},{"alias_kind":"pith_short_8","alias_value":"OQVTQYIQ","created_at":"2026-07-05T02:01:30Z"}],"graph_snapshots":[{"event_id":"sha256:45b3d63e1b994b32846a0f4c470e2f7e08a08f8e440ef003a34a873a01906852","target":"graph","created_at":"2026-07-05T02:01:30Z","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"},"integrity":{"available":true,"clean":true,"detectors_run":[],"endpoint":"/pith/2007.00476/integrity.json","findings":[],"snapshot_sha256":"c28c3603d3b5d939e8dc4c7e95fa8dfce3d595e45f758748cecf8e644a296938","summary":{"advisory":0,"by_detector":{},"critical":0,"informational":0}},"paper":{"abstract_excerpt":"The quasi-harmonic model proposes that a crystal can be modeled as atoms connected by springs. We demonstrate how this viewpoint can be misleading: a simple application of Gauss' law shows that the ion-ion potential for a cubic Coulomb system can have no diagonal harmonic contribution and so cannot necessarily be modeled by springs. We investigate the repercussions of this observation by examining three illustrative regimes: the bare ionic, density tight-binding, and density nearly-free electron models. For the bare ionic model, we demonstrate the zero elements in the force constants matrix an","authors_text":"Bartholomew Andrews, Gareth Conduit","cross_cats":["cond-mat.other"],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cond-mat.mtrl-sci","submitted_at":"2020-07-01T13:31:38Z","title":"Absence of diagonal force constants in cubic Coulomb crystals"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"2007.00476","kind":"arxiv","version":2},"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:fa4967d451725fc69e1711d3915576e8a9106f8dbd9cb7505ea31f18abd42cbb","target":"record","created_at":"2026-07-05T02:01:30Z","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":"44c3a6636fdaa1bb26b9bbada0a43ebae54a292017f1c5aedff5fc5a84681999","cross_cats_sorted":["cond-mat.other"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cond-mat.mtrl-sci","submitted_at":"2020-07-01T13:31:38Z","title_canon_sha256":"bfd025e664c9fc578c1b26ac9094ce01a53a393e46ff28e961ddb6a4ecfa97fd"},"schema_version":"1.0","source":{"id":"2007.00476","kind":"arxiv","version":2}},"canonical_sha256":"742b38611045187f882e4cf77ad8f9ea8d5f39ee2605de91f6277145a62924d9","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"742b38611045187f882e4cf77ad8f9ea8d5f39ee2605de91f6277145a62924d9","first_computed_at":"2026-07-05T02:01:30.692636Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-07-05T02:01:30.692636Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"bg/vcRvvpUF96sUnrXwg/jxuRxkvc+uf5is39xjKuR6DbwPjohL8M66dR3YNQXpO1Bc8nbKRMBprrksJCoSqCQ==","signature_status":"signed_v1","signed_at":"2026-07-05T02:01:30.693125Z","signed_message":"canonical_sha256_bytes"},"source_id":"2007.00476","source_kind":"arxiv","source_version":2}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:fa4967d451725fc69e1711d3915576e8a9106f8dbd9cb7505ea31f18abd42cbb","sha256:45b3d63e1b994b32846a0f4c470e2f7e08a08f8e440ef003a34a873a01906852"],"state_sha256":"0dab5d34d7d0c0d2ceefbc314ab49f026c20f5fb5914d124fef100920a800b0a"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"5IMRqfZ0HejPczW9CINNcXHtbbpKrxJxF5VGarYXzvovRsfPvwlNePfnXBZuwDuLbDUf/rUJPRcTXPi6r8mFAA==","signed_message":"bundle_sha256_bytes","signed_at":"2026-08-05T11:15:24.969428Z","bundle_sha256":"c7ded15905c832ffb1442a5d3ecb5362cb2adfd977d64b25e3af4173d206554a"}}