{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2020:HSQWASBKS7LN3CZDWAXNUVXHUA","short_pith_number":"pith:HSQWASBK","canonical_record":{"source":{"id":"2003.00486","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cond-mat.mtrl-sci","submitted_at":"2020-03-01T13:23:48Z","cross_cats_sorted":[],"title_canon_sha256":"b2ca8212ca570a1d219bf1c84e03048f2edaa7a2a198237ab4f8e0ab8dee268a","abstract_canon_sha256":"b7ae853292e13298ea84d56a76e97e0c09f4fb0d754aa46eee007fbe42b29ed3"},"schema_version":"1.0"},"canonical_sha256":"3ca160482a97d6dd8b23b02eda56e7a007b3a54eb022e638a85ed7648ee42596","source":{"kind":"arxiv","id":"2003.00486","version":1},"source_aliases":[{"alias_kind":"arxiv","alias_value":"2003.00486","created_at":"2026-07-05T01:00:40Z"},{"alias_kind":"arxiv_version","alias_value":"2003.00486v1","created_at":"2026-07-05T01:00:40Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.2003.00486","created_at":"2026-07-05T01:00:40Z"},{"alias_kind":"pith_short_12","alias_value":"HSQWASBKS7LN","created_at":"2026-07-05T01:00:40Z"},{"alias_kind":"pith_short_16","alias_value":"HSQWASBKS7LN3CZD","created_at":"2026-07-05T01:00:40Z"},{"alias_kind":"pith_short_8","alias_value":"HSQWASBK","created_at":"2026-07-05T01:00:40Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2020:HSQWASBKS7LN3CZDWAXNUVXHUA","target":"record","payload":{"canonical_record":{"source":{"id":"2003.00486","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cond-mat.mtrl-sci","submitted_at":"2020-03-01T13:23:48Z","cross_cats_sorted":[],"title_canon_sha256":"b2ca8212ca570a1d219bf1c84e03048f2edaa7a2a198237ab4f8e0ab8dee268a","abstract_canon_sha256":"b7ae853292e13298ea84d56a76e97e0c09f4fb0d754aa46eee007fbe42b29ed3"},"schema_version":"1.0"},"canonical_sha256":"3ca160482a97d6dd8b23b02eda56e7a007b3a54eb022e638a85ed7648ee42596","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-07-05T01:00:40.971284Z","signature_b64":"MoC5LBRIyJwJLGEtJkkd9s7zdhggBJFsZZMkIyarJtocCgMkGTYEXTXNNod/H+RZihdw6ZdDu/QTI0ARGv1dDw==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"3ca160482a97d6dd8b23b02eda56e7a007b3a54eb022e638a85ed7648ee42596","last_reissued_at":"2026-07-05T01:00:40.970817Z","signature_status":"signed_v1","first_computed_at":"2026-07-05T01:00:40.970817Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"2003.00486","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":"2026-07-05T01:00:40Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"48TcwVijylixILUpb14s0icoSV9G4chLu+737V66GHFyq/MJiDkXIB6NVQTU7ZUOJ4hy6u3/GneC6E/7AElfCg==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-08-11T00:46:45.866447Z"},"content_sha256":"1560461eaeec786873ccac53c144954a73061cf5a9b946ebb491c9ce120a1df3","schema_version":"1.0","event_id":"sha256:1560461eaeec786873ccac53c144954a73061cf5a9b946ebb491c9ce120a1df3"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2020:HSQWASBKS7LN3CZDWAXNUVXHUA","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"Bi2W2O9: a potentially antiferroelectric Aurivillius phase","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"cond-mat.mtrl-sci","authors_text":"A. Feteira, E. Bousquet, Emma. E. McCabe, Hania Djani, J. Bieder, Ph. Ghosez, P. S. Halasyamani, W. Zhang","submitted_at":"2020-03-01T13:23:48Z","abstract_excerpt":"Ferroelectric tungsten-based Aurivillius oxides are naturally stable superlattice structures, in which A-site deficient perovskite blocks [WnO3n+1]-2 (n = 1, 2, 3, ...) interleave with fluorite-like bismuth oxide layers [Bi2O2]+2 along the c -axis. In the n = 2 Bi2W2O9 phase, an in-plane antipolar distortion dominates but there has been controversy as to the ground state symmetry. Here we show, using a combination of first-principles density functional theory calculations and experiments, that the ground state is a non-polar phase of Pnab symmetry. We explore the energetics of metastable phase"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"2003.00486","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/2003.00486/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":"2026-07-05T01:00:40Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"ft365fdKsBDrOkWNrpUk6NMwtLB7dvA8ZqL9majntcVSUphXuWFpDss1bLyzJabjqm86X2QZ79vs5TUrS7RyDA==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-08-11T00:46:45.867471Z"},"content_sha256":"10f540703067ff7f14f3790d5e05f6435a4903b12ddece3a6e141d5a4a7fee2f","schema_version":"1.0","event_id":"sha256:10f540703067ff7f14f3790d5e05f6435a4903b12ddece3a6e141d5a4a7fee2f"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/HSQWASBKS7LN3CZDWAXNUVXHUA/bundle.json","state_url":"https://pith.science/pith/HSQWASBKS7LN3CZDWAXNUVXHUA/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/HSQWASBKS7LN3CZDWAXNUVXHUA/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":"2026-08-11T00:46:45Z","links":{"resolver":"https://pith.science/pith/HSQWASBKS7LN3CZDWAXNUVXHUA","bundle":"https://pith.science/pith/HSQWASBKS7LN3CZDWAXNUVXHUA/bundle.json","state":"https://pith.science/pith/HSQWASBKS7LN3CZDWAXNUVXHUA/state.json","well_known_bundle":"https://pith.science/.well-known/pith/HSQWASBKS7LN3CZDWAXNUVXHUA/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2020:HSQWASBKS7LN3CZDWAXNUVXHUA","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":"b7ae853292e13298ea84d56a76e97e0c09f4fb0d754aa46eee007fbe42b29ed3","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cond-mat.mtrl-sci","submitted_at":"2020-03-01T13:23:48Z","title_canon_sha256":"b2ca8212ca570a1d219bf1c84e03048f2edaa7a2a198237ab4f8e0ab8dee268a"},"schema_version":"1.0","source":{"id":"2003.00486","kind":"arxiv","version":1}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"2003.00486","created_at":"2026-07-05T01:00:40Z"},{"alias_kind":"arxiv_version","alias_value":"2003.00486v1","created_at":"2026-07-05T01:00:40Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.2003.00486","created_at":"2026-07-05T01:00:40Z"},{"alias_kind":"pith_short_12","alias_value":"HSQWASBKS7LN","created_at":"2026-07-05T01:00:40Z"},{"alias_kind":"pith_short_16","alias_value":"HSQWASBKS7LN3CZD","created_at":"2026-07-05T01:00:40Z"},{"alias_kind":"pith_short_8","alias_value":"HSQWASBK","created_at":"2026-07-05T01:00:40Z"}],"graph_snapshots":[{"event_id":"sha256:10f540703067ff7f14f3790d5e05f6435a4903b12ddece3a6e141d5a4a7fee2f","target":"graph","created_at":"2026-07-05T01:00:40Z","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/2003.00486/integrity.json","findings":[],"snapshot_sha256":"c28c3603d3b5d939e8dc4c7e95fa8dfce3d595e45f758748cecf8e644a296938","summary":{"advisory":0,"by_detector":{},"critical":0,"informational":0}},"paper":{"abstract_excerpt":"Ferroelectric tungsten-based Aurivillius oxides are naturally stable superlattice structures, in which A-site deficient perovskite blocks [WnO3n+1]-2 (n = 1, 2, 3, ...) interleave with fluorite-like bismuth oxide layers [Bi2O2]+2 along the c -axis. In the n = 2 Bi2W2O9 phase, an in-plane antipolar distortion dominates but there has been controversy as to the ground state symmetry. Here we show, using a combination of first-principles density functional theory calculations and experiments, that the ground state is a non-polar phase of Pnab symmetry. We explore the energetics of metastable phase","authors_text":"A. Feteira, E. Bousquet, Emma. E. McCabe, Hania Djani, J. Bieder, Ph. Ghosez, P. S. Halasyamani, W. Zhang","cross_cats":[],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cond-mat.mtrl-sci","submitted_at":"2020-03-01T13:23:48Z","title":"Bi2W2O9: a potentially antiferroelectric Aurivillius phase"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"2003.00486","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":"sha256:1560461eaeec786873ccac53c144954a73061cf5a9b946ebb491c9ce120a1df3","target":"record","created_at":"2026-07-05T01:00:40Z","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":"b7ae853292e13298ea84d56a76e97e0c09f4fb0d754aa46eee007fbe42b29ed3","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cond-mat.mtrl-sci","submitted_at":"2020-03-01T13:23:48Z","title_canon_sha256":"b2ca8212ca570a1d219bf1c84e03048f2edaa7a2a198237ab4f8e0ab8dee268a"},"schema_version":"1.0","source":{"id":"2003.00486","kind":"arxiv","version":1}},"canonical_sha256":"3ca160482a97d6dd8b23b02eda56e7a007b3a54eb022e638a85ed7648ee42596","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"3ca160482a97d6dd8b23b02eda56e7a007b3a54eb022e638a85ed7648ee42596","first_computed_at":"2026-07-05T01:00:40.970817Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-07-05T01:00:40.970817Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"MoC5LBRIyJwJLGEtJkkd9s7zdhggBJFsZZMkIyarJtocCgMkGTYEXTXNNod/H+RZihdw6ZdDu/QTI0ARGv1dDw==","signature_status":"signed_v1","signed_at":"2026-07-05T01:00:40.971284Z","signed_message":"canonical_sha256_bytes"},"source_id":"2003.00486","source_kind":"arxiv","source_version":1}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:1560461eaeec786873ccac53c144954a73061cf5a9b946ebb491c9ce120a1df3","sha256:10f540703067ff7f14f3790d5e05f6435a4903b12ddece3a6e141d5a4a7fee2f"],"state_sha256":"26d943ec450955b24ed9a10db515b750c3f0d568b925da850d372af82eaa3585"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"MoiUpGzaNnh3KQBUd4IScm/KsnWtpFPBlnumZkLwE/rcRGNAWaY84Ke2WV7xpTZ1qpP4Qth2mOVWGuePh3+WCg==","signed_message":"bundle_sha256_bytes","signed_at":"2026-08-11T00:46:45.875968Z","bundle_sha256":"90b2c835f8c5ad189b433bcc09fb3ba5c4d3636b5ddb7eeafb50e9c070596744"}}