{
  "alternatives": [
    "permittivity-T/cln/cti1999",
    "permittivity-T/cln/volk2008"
  ],
  "meta": {
    "api_version": "v1",
    "attribution": "lithium-niobate.com data compiled by Wentao Jiang; cite the original sources listed per value.",
    "data_version": "0.1.0",
    "documentation": "https://lithium-niobate.com/api/openapi.json",
    "license": {
      "id": "CC-BY-4.0",
      "name": "Creative Commons Attribution 4.0 International",
      "url": "https://creativecommons.org/licenses/by/4.0/"
    },
    "tensor": "permittivity-T",
    "variant": "cln"
  },
  "recommended": {
    "conditions": {
      "frequency_text": "low frequency (below acoustic resonances)",
      "mechanical_boundary": "T",
      "method": "measured"
    },
    "consistency": [
      {
        "check": "eps^T = eps^S + d e^T / eps0 from the kushibiki1999 eps^S, e and derived d",
        "result": "eps11^T = 83.3, eps33^T = 28.5 (measured 83.3, 28.5)",
        "status": "C"
      }
    ],
    "default": true,
    "frame": {
      "convention": "unstated",
      "handedness": "right",
      "setting": "crystal-physics",
      "x": "a axis, perpendicular to a mirror plane",
      "y": "in a mirror plane",
      "z": "polar c axis",
      "z_sign_definition": "not stated in this record; tensor form matches this frame by symmetry"
    },
    "full": [
      [
        83.3,
        0.0,
        0.0
      ],
      [
        0.0,
        83.3,
        0.0
      ],
      [
        0.0,
        0.0,
        28.5
      ]
    ],
    "id": "permittivity-T/cln/kushibiki1999",
    "independent": {
      "eps11": {
        "uncertainty": {
          "type": "stated",
          "value": 0.8
        },
        "value": 83.3
      },
      "eps33": {
        "uncertainty": {
          "type": "stated",
          "value": 0.3
        },
        "value": 28.5
      }
    },
    "kind": "tensor",
    "name": "Relative permittivity, constant stress (free)",
    "provenance": {
      "locator": "Table IV",
      "source_id": "kushibiki1999",
      "status": "P",
      "transcribed": "2026-10-25"
    },
    "public": true,
    "rank": 2,
    "scale": 1,
    "symbol": "eps^T/eps0",
    "symmetry_form": {
      "form": [
        [
          "eps11",
          "0",
          "0"
        ],
        [
          "0",
          "eps11",
          "0"
        ],
        [
          "0",
          "0",
          "eps33"
        ]
      ],
      "mirror": "x = 0 plane (x perpendicular to the mirror, z polar)",
      "point_group": "3m",
      "relations": [
        "eps22 = eps11",
        "off-diagonal = 0"
      ]
    },
    "tensor": "permittivity-T",
    "unit": {
      "display": "relative (eps/eps0)",
      "qudt": "http://qudt.org/vocab/unit/UNITLESS",
      "ucum": "1"
    },
    "variant": "cln",
    "variant_note": "SAW-grade congruent; composition not stated in the source",
    "voigt": [
      [
        83.3,
        0.0,
        0.0
      ],
      [
        0.0,
        83.3,
        0.0
      ],
      [
        0.0,
        0.0,
        28.5
      ]
    ],
    "voigt_convention": {
      "full_from_voigt": "full[i][j] = M[i][j]",
      "order": [
        "x",
        "y",
        "z"
      ]
    }
  },
  "recommended_note": null,
  "spread": {
    "eps11": {
      "max": 85,
      "min": 83.3,
      "n_records": 3
    },
    "eps33": {
      "max": 30,
      "min": 28.5,
      "n_records": 3
    }
  }
}