{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2015:DJXJAR7MO62NQVPUORAAVA53F2","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":"ac3f35f538d942ac29383b45a3ecbf0091beffc52db50f17ef60491044232be8","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"physics.chem-ph","submitted_at":"2015-03-25T14:59:55Z","title_canon_sha256":"c9928c6591b4e7a2535a35b7e76996ea669a28e8b66e010eb34e35a09718fd4a"},"schema_version":"1.0","source":{"id":"1503.07406","kind":"arxiv","version":1}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1503.07406","created_at":"2026-05-18T02:20:21Z"},{"alias_kind":"arxiv_version","alias_value":"1503.07406v1","created_at":"2026-05-18T02:20:21Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1503.07406","created_at":"2026-05-18T02:20:21Z"},{"alias_kind":"pith_short_12","alias_value":"DJXJAR7MO62N","created_at":"2026-05-18T12:29:17Z"},{"alias_kind":"pith_short_16","alias_value":"DJXJAR7MO62NQVPU","created_at":"2026-05-18T12:29:17Z"},{"alias_kind":"pith_short_8","alias_value":"DJXJAR7M","created_at":"2026-05-18T12:29:17Z"}],"graph_snapshots":[{"event_id":"sha256:c1676355c8a909695399c7b552f2ed7dabd627b88ffc94fbe24fa8e62f546c12","target":"graph","created_at":"2026-05-18T02:20:21Z","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 introduce and evaluate a set of feature vector representations of crystal structures for machine learning (ML) models of formation energies of solids. ML models of atomization energies of organic molecules have been successful using a Coulomb matrix representation of the molecule. We consider three ways to generalize such representations to periodic systems: (i) a matrix where each element is related to the Ewald sum of the electrostatic interaction between two different atoms in the unit cell repeated over the lattice; (ii) an extended Coulomb-like matrix that takes into account a number o","authors_text":"Alexander Lindmaa, Felix Faber, O. Anatole von Lilienfeld, Rickard Armiento","cross_cats":[],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"physics.chem-ph","submitted_at":"2015-03-25T14:59:55Z","title":"Crystal Structure Representations for Machine Learning Models of Formation Energies"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1503.07406","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:e3e88af43ee7eaf00c7d11ea473c0f0d996825e90b78b87ae797f40869f73922","target":"record","created_at":"2026-05-18T02:20:21Z","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":"ac3f35f538d942ac29383b45a3ecbf0091beffc52db50f17ef60491044232be8","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"physics.chem-ph","submitted_at":"2015-03-25T14:59:55Z","title_canon_sha256":"c9928c6591b4e7a2535a35b7e76996ea669a28e8b66e010eb34e35a09718fd4a"},"schema_version":"1.0","source":{"id":"1503.07406","kind":"arxiv","version":1}},"canonical_sha256":"1a6e9047ec77b4d855f474400a83bb2e999b0cae416a03aae35689708d44135d","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"1a6e9047ec77b4d855f474400a83bb2e999b0cae416a03aae35689708d44135d","first_computed_at":"2026-05-18T02:20:21.145466Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-05-18T02:20:21.145466Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"82pAbgdX/9tsEqFs22VOk/KRI/DafIccXagK7zt17KoHwtZBDS/jMIGdLX3ff/sOOspA3b5gEnD0bAwdIRQWBA==","signature_status":"signed_v1","signed_at":"2026-05-18T02:20:21.146088Z","signed_message":"canonical_sha256_bytes"},"source_id":"1503.07406","source_kind":"arxiv","source_version":1}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:e3e88af43ee7eaf00c7d11ea473c0f0d996825e90b78b87ae797f40869f73922","sha256:c1676355c8a909695399c7b552f2ed7dabd627b88ffc94fbe24fa8e62f546c12"],"state_sha256":"b903d78eafbde77532b585c2a52f376d7e4182a6e8ee8e2bd8e582e8cc5d9293"}