{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2017:42NCSEVOSU4A6POWBLOKMXNKKI","short_pith_number":"pith:42NCSEVO","canonical_record":{"source":{"id":"1712.01306","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cond-mat.mtrl-sci","submitted_at":"2017-12-04T19:06:20Z","cross_cats_sorted":[],"title_canon_sha256":"3c7e1a4964d289206751c91390bac28921b34815cdec0e9e62ef6bfecce8699d","abstract_canon_sha256":"4834b91d539bada884f40d971a38aafcaaadfa13f0602231704f2a4bf5486875"},"schema_version":"1.0"},"canonical_sha256":"e69a2912ae95380f3dd60adca65daa5219c4086ff841c4b0fa8f8f0c7da07798","source":{"kind":"arxiv","id":"1712.01306","version":1},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1712.01306","created_at":"2026-05-18T00:28:51Z"},{"alias_kind":"arxiv_version","alias_value":"1712.01306v1","created_at":"2026-05-18T00:28:51Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1712.01306","created_at":"2026-05-18T00:28:51Z"},{"alias_kind":"pith_short_12","alias_value":"42NCSEVOSU4A","created_at":"2026-05-18T12:30:58Z"},{"alias_kind":"pith_short_16","alias_value":"42NCSEVOSU4A6POW","created_at":"2026-05-18T12:30:58Z"},{"alias_kind":"pith_short_8","alias_value":"42NCSEVO","created_at":"2026-05-18T12:30:58Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2017:42NCSEVOSU4A6POWBLOKMXNKKI","target":"record","payload":{"canonical_record":{"source":{"id":"1712.01306","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cond-mat.mtrl-sci","submitted_at":"2017-12-04T19:06:20Z","cross_cats_sorted":[],"title_canon_sha256":"3c7e1a4964d289206751c91390bac28921b34815cdec0e9e62ef6bfecce8699d","abstract_canon_sha256":"4834b91d539bada884f40d971a38aafcaaadfa13f0602231704f2a4bf5486875"},"schema_version":"1.0"},"canonical_sha256":"e69a2912ae95380f3dd60adca65daa5219c4086ff841c4b0fa8f8f0c7da07798","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-05-18T00:28:51.168732Z","signature_b64":"9WgdPPgpznhIOni2kjOfjP70dqj2YoGR3RyEn84xlmBVSy7yIjRqsPNDjkMurcwsBs0VuW/1gvvv6GiLVc3aAg==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"e69a2912ae95380f3dd60adca65daa5219c4086ff841c4b0fa8f8f0c7da07798","last_reissued_at":"2026-05-18T00:28:51.168041Z","signature_status":"signed_v1","first_computed_at":"2026-05-18T00:28:51.168041Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"1712.01306","source_version":1,"attestation_state":"computed"},"signer":{"signer_id":"pith.science","signer_type":"pith_registry","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"created_at":"2026-05-18T00:28:51Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"dSuBMPVC1zLKW+ml9FcCmrqLfstOqjMuUWFGBOn1eWRa/Z2xL6T7+TZ7VAbTkGZpt1lZwJiSTS7p2uVfIUQSBw==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-05-25T20:08:28.398829Z"},"content_sha256":"abc9f71ede5b8480a129e7501cd161e27585ff112435985150ba6b81e774463d","schema_version":"1.0","event_id":"sha256:abc9f71ede5b8480a129e7501cd161e27585ff112435985150ba6b81e774463d"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2017:42NCSEVOSU4A6POWBLOKMXNKKI","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"Recipes for improper ferroelectricity in hybrid perovskites","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"cond-mat.mtrl-sci","authors_text":"Andrew L Goodwin, Hanna L B Bostr\\\"om, Mark S Senn","submitted_at":"2017-12-04T19:06:20Z","abstract_excerpt":"The central goal of crystal engineering is to develop precise control over material function \\emph{via} rational design of structure. A particularly successful realisation of this paradigm is the example of hybrid improper ferroelectricity in layered perovskite materials, where cation vacancies and cooperative octahedral tilts combine to break inversion symmetry. However, in the more chemically diverse and technologically relevant family of inorganic ABX$_3$ perovskites, symmetry conspires to render hybrid coupling to polar distortions impossible. In this study, we use group-theoretical analys"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1712.01306","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":""},"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":"2026-05-18T00:28:51Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"tDab2SZLr1YHR0IDGVMwuGSu3hLP11i1Xo120huJzo1zOIZLbmkYV6v3GvKZdvuug4PFq/k2K4NHC6u7yHyXAg==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-05-25T20:08:28.399414Z"},"content_sha256":"6650d3fc355910e8312d6117d5833bafc49c74e523f4dbf5f18154d749c67767","schema_version":"1.0","event_id":"sha256:6650d3fc355910e8312d6117d5833bafc49c74e523f4dbf5f18154d749c67767"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/42NCSEVOSU4A6POWBLOKMXNKKI/bundle.json","state_url":"https://pith.science/pith/42NCSEVOSU4A6POWBLOKMXNKKI/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/42NCSEVOSU4A6POWBLOKMXNKKI/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":"2026-05-25T20:08:28Z","links":{"resolver":"https://pith.science/pith/42NCSEVOSU4A6POWBLOKMXNKKI","bundle":"https://pith.science/pith/42NCSEVOSU4A6POWBLOKMXNKKI/bundle.json","state":"https://pith.science/pith/42NCSEVOSU4A6POWBLOKMXNKKI/state.json","well_known_bundle":"https://pith.science/.well-known/pith/42NCSEVOSU4A6POWBLOKMXNKKI/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2017:42NCSEVOSU4A6POWBLOKMXNKKI","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":"4834b91d539bada884f40d971a38aafcaaadfa13f0602231704f2a4bf5486875","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cond-mat.mtrl-sci","submitted_at":"2017-12-04T19:06:20Z","title_canon_sha256":"3c7e1a4964d289206751c91390bac28921b34815cdec0e9e62ef6bfecce8699d"},"schema_version":"1.0","source":{"id":"1712.01306","kind":"arxiv","version":1}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1712.01306","created_at":"2026-05-18T00:28:51Z"},{"alias_kind":"arxiv_version","alias_value":"1712.01306v1","created_at":"2026-05-18T00:28:51Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1712.01306","created_at":"2026-05-18T00:28:51Z"},{"alias_kind":"pith_short_12","alias_value":"42NCSEVOSU4A","created_at":"2026-05-18T12:30:58Z"},{"alias_kind":"pith_short_16","alias_value":"42NCSEVOSU4A6POW","created_at":"2026-05-18T12:30:58Z"},{"alias_kind":"pith_short_8","alias_value":"42NCSEVO","created_at":"2026-05-18T12:30:58Z"}],"graph_snapshots":[{"event_id":"sha256:6650d3fc355910e8312d6117d5833bafc49c74e523f4dbf5f18154d749c67767","target":"graph","created_at":"2026-05-18T00:28:51Z","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":"The central goal of crystal engineering is to develop precise control over material function \\emph{via} rational design of structure. A particularly successful realisation of this paradigm is the example of hybrid improper ferroelectricity in layered perovskite materials, where cation vacancies and cooperative octahedral tilts combine to break inversion symmetry. However, in the more chemically diverse and technologically relevant family of inorganic ABX$_3$ perovskites, symmetry conspires to render hybrid coupling to polar distortions impossible. In this study, we use group-theoretical analys","authors_text":"Andrew L Goodwin, Hanna L B Bostr\\\"om, Mark S Senn","cross_cats":[],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cond-mat.mtrl-sci","submitted_at":"2017-12-04T19:06:20Z","title":"Recipes for improper ferroelectricity in hybrid perovskites"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1712.01306","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:abc9f71ede5b8480a129e7501cd161e27585ff112435985150ba6b81e774463d","target":"record","created_at":"2026-05-18T00:28:51Z","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":"4834b91d539bada884f40d971a38aafcaaadfa13f0602231704f2a4bf5486875","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cond-mat.mtrl-sci","submitted_at":"2017-12-04T19:06:20Z","title_canon_sha256":"3c7e1a4964d289206751c91390bac28921b34815cdec0e9e62ef6bfecce8699d"},"schema_version":"1.0","source":{"id":"1712.01306","kind":"arxiv","version":1}},"canonical_sha256":"e69a2912ae95380f3dd60adca65daa5219c4086ff841c4b0fa8f8f0c7da07798","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"e69a2912ae95380f3dd60adca65daa5219c4086ff841c4b0fa8f8f0c7da07798","first_computed_at":"2026-05-18T00:28:51.168041Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-05-18T00:28:51.168041Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"9WgdPPgpznhIOni2kjOfjP70dqj2YoGR3RyEn84xlmBVSy7yIjRqsPNDjkMurcwsBs0VuW/1gvvv6GiLVc3aAg==","signature_status":"signed_v1","signed_at":"2026-05-18T00:28:51.168732Z","signed_message":"canonical_sha256_bytes"},"source_id":"1712.01306","source_kind":"arxiv","source_version":1}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:abc9f71ede5b8480a129e7501cd161e27585ff112435985150ba6b81e774463d","sha256:6650d3fc355910e8312d6117d5833bafc49c74e523f4dbf5f18154d749c67767"],"state_sha256":"208b201bd714434db56c890519c1cbb7cefddd816c265a1ad935528bc72c00d7"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"a+yI2pU1foeME//7g3mEbFQSJ8zJk9d7x8Q3G2cB0Ju/ithNeJuzknzz9dzY0sDLtgnRdadYKxRs2n6CyfBsBg==","signed_message":"bundle_sha256_bytes","signed_at":"2026-05-25T20:08:28.402937Z","bundle_sha256":"97c5fbda233d77e1f34e7a775d9368c770d01acbe20812369f257428282e8acf"}}