{
  "@context": {
    "schema": "http://schema.org/",
    "dcterms": "http://purl.org/dc/terms/",
    "geosparql": "http://www.opengis.net/ont/geosparql#",
    "spdx": "http://spdx.org/rdf/terms#",
    "cdi": "http://ddialliance.org/Specification/DDI-CDI/1.0/RDF/",
    "prov": "http://www.w3.org/ns/prov#",
    "xas": "https://xas.org/dictionary/",
    "nxs": "http://purl.org/nexusformat/definitions/",
    "dcat": "http://www.w3.org/ns/dcat#"
  },
  "@id": "ex:xasOptionalExample_001",
  "@type": [
    "schema:Dataset",
    "schema:Product"
  ],
  "schema:name": "XAS measurement of Fe K-edge in magnetite sample",
  "schema:identifier": {
    "@type": [
      "schema:PropertyValue"
    ],
    "schema:propertyID": "https://doi.org",
    "schema:value": "10.12345/xas-optional-test",
    "schema:url": "https://doi.org/10.12345/xas-optional-test"
  },
  "schema:dateModified": "2026-01-15",
  "schema:license": [
    "https://creativecommons.org/licenses/by/4.0/"
  ],
  "schema:distribution": [
    {
      "@id": "ex:dist_xdi_001",
      "@type": [
        "schema:DataDownload",
        "cdi:PhysicalDataset"
      ],
      "schema:name": "XDI data file for Fe K-edge magnetite",
      "schema:contentUrl": "https://example.org/data/fe_magnetite_kedge_01.xdi",
      "schema:encodingFormat": [
        "text/plain"
      ],
      "dcterms:conformsTo": [
        {
          "@id": "https://github.com/XraySpectroscopy/XAS-Data-Interchange/blob/master/specification/spec.md"
        }
      ],
      "spdx:checksum": {
        "@type": [
          "spdx:Checksum"
        ],
        "spdx:algorithm": "SHA256",
        "spdx:checksumValue": "a1b2c3d4e5f6"
      }
    }
  ],
  "schema:subjectOf": {
    "@type": [
      "schema:Dataset"
    ],
    "schema:additionalType": [
      "dcat:CatalogRecord"
    ],
    "@id": "ex:meta_xasOpt_001",
    "schema:about": {
      "@id": "ex:xasOptionalExample_001"
    },
    "dcterms:conformsTo": [
      {
        "@id": "https://w3id.org/cdif/core/1.1"
      },
      {
        "@id": "https://w3id.org/cdif/discovery/1.1"
      },
      {
        "@id": "https://w3id.org/cdif/xasDiscovery/1.0"
      },
      {
        "@id": "https://w3id.org/cdif/bbr/metadata/xasProperties/xasOptional"
      },
      {
        "@id": "https://w3id.org/cdif/data_description/1.1"
      },
      {
        "@id": "https://w3id.org/cdif/xasCore/1.0"
      }
    ],
    "schema:maintainer": {
      "@id": "ex:person_jdoe",
      "@type": [
        "schema:Person"
      ],
      "schema:name": "Doe, Jane",
      "schema:contactPoint": {
        "@type": [
          "schema:ContactPoint"
        ],
        "schema:email": "jane.doe@example.org"
      }
    },
    "schema:sdDatePublished": "2026-01-20T10:00:00Z"
  },
  "prov:wasGeneratedBy": [
    {
      "prov:used": [
        {
          "schema:instrument": {
            "@type": [
              "schema:Thing",
              "schema:Product"
            ],
            "schema:name": "APS Sector 20-BM beamline instrument",
            "schema:category": [
              {
                "@type": [
                  "schema:DefinedTerm"
                ],
                "schema:name": "X-ray absorption spectroscopy beamline",
                "schema:termCode": "XAS-beamline"
              }
            ],
            "schema:hasPart": [
              {
                "@type": [
                  "schema:Thing",
                  "schema:Product"
                ],
                "schema:additionalType": "nxs:BaseClass/NXsource",
                "schema:name": "APS Undulator A",
                "schema:additionalProperty": [
                  {
                    "@type": [
                      "schema:PropertyValue"
                    ],
                    "schema:propertyID": [
                      "nxs:Field/NXsource/type"
                    ],
                    "schema:name": "x-ray source type",
                    "schema:value": "Synchrotron X-ray Source"
                  },
                  {
                    "@type": [
                      "schema:PropertyValue"
                    ],
                    "schema:propertyID": [
                      "nxs:Field/NXsource/probe"
                    ],
                    "schema:name": "Probe",
                    "schema:value": "x-ray"
                  }
                ]
              },
              {
                "@type": [
                  "schema:Thing",
                  "schema:Product"
                ],
                "schema:additionalType": "nxs:BaseClass/NXmonochromator",
                "schema:name": "Si 311",
                "schema:additionalProperty": [
                  {
                    "@type": [
                      "schema:PropertyValue"
                    ],
                    "schema:propertyID": [
                      "nxs:Field/NXcrystal/d_spacing"
                    ],
                    "schema:name": "d-spacing",
                    "schema:value": "1.63747",
                    "schema:unitText": "Angstrom"
                  },
                  {
                    "@type": [
                      "schema:PropertyValue"
                    ],
                    "schema:propertyID": [
                      "nxs:Field/NXcrystal/type"
                    ],
                    "schema:name": "crystal type",
                    "schema:value": "channel-cut"
                  },
                  {
                    "@type": [
                      "schema:PropertyValue"
                    ],
                    "schema:propertyID": [
                      "nxs:Field/NXcrystal/reflection"
                    ],
                    "schema:name": "reflection plane (hkl)",
                    "schema:value": "3,1,1"
                  }
                ]
              }
            ]
          }
        }
      ],
      "schema:object": {
        "@type": [
          "schema:Product",
          "schema:Thing"
        ],
        "schema:additionalType": [
          "MaterialSample",
          "https://w3id.org/isample/vocabulary/materialsampleobjecttype/materialsample"
        ],
        "schema:name": "Magnetite powder",
        "schema:identifier": "igsn:10.60471/mag-001",
        "schema:description": "Synthetic magnetite powder, 99.5% purity",
        "schema:additionalProperty": [
          {
            "@type": [
              "schema:PropertyValue"
            ],
            "schema:propertyID": [
              "xas:stoichiometry"
            ],
            "schema:name": "Stoichiometry",
            "schema:value": "Fe3O4"
          },
          {
            "@type": [
              "schema:PropertyValue"
            ],
            "schema:propertyID": [
              "xas:samplePreparation"
            ],
            "schema:name": "sample preparation method",
            "schema:value": "ground and pressed into pellet with BN diluent"
          }
        ]
      }
    }
  ],
  "schema:measurementTechnique": [
    {
      "@type": [
        "schema:DefinedTerm"
      ],
      "schema:name": "X-Ray Absorption Spectroscopy",
      "schema:termCode": "XAS",
      "schema:identifier": "http://purl.org/pan-science/PaNET/PaNET01196",
      "schema:inDefinedTermSet": "http://purl.org/pan-science/PaNET/PaNET.owl"
    },
    {
      "@type": [
        "schema:DefinedTerm"
      ],
      "schema:name": "Transmission",
      "schema:identifier": "xas:transmissionMode",
      "schema:inDefinedTermSet": "nxs:Field/NXxas/ENTRY/DATA/mode"
    }
  ],
  "schema:keywords": [
    {
      "@type": [
        "schema:DefinedTerm"
      ],
      "schema:name": "K-edge",
      "schema:identifier": "xas:K-edge",
      "schema:termCode": "K",
      "schema:inDefinedTermSet": "https://github.com/XraySpectroscopy/XAS-Data-Interchange/blob/master/specification/dictionary.md"
    },
    {
      "@type": [
        "schema:DefinedTerm"
      ],
      "schema:name": "Iron",
      "schema:identifier": "http://sweetontology.net/matrElement/Iron",
      "schema:termCode": "Fe",
      "schema:inDefinedTermSet": "http://sweetontology.net/matrElement"
    }
  ],
  "schema:variableMeasured": [
    {
      "@id": "xas:monochromatorEnergy",
      "@type": [
        "cdi:InstanceVariable",
        "schema:PropertyValue"
      ],
      "schema:name": "energy",
      "schema:alternateName": [
        "Monochromator energy"
      ],
      "schema:description": "Monochromator energy at which the XAS spectrum was acquired.",
      "schema:propertyID": [
        "xas:monochromatorEnergyConcept"
      ],
      "schema:unitText": "eV",
      "cdi:identifier": "xas:monochromatorEnergy",
      "cdi:physicalDataType": [
        "xsd:decimal"
      ],
      "cdi:simpleUnitOfMeasure": "eV"
    }
  ]
}