{
  "alternatives": [
    "eo-rT/cln/cti1999"
  ],
  "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": "eo-rT",
    "variant": "cln"
  },
  "recommended": {
    "conditions": {
      "mechanical_boundary": "T",
      "wavelength_nm": 633
    },
    "default": true,
    "frame": {
      "convention": "IRE-1949",
      "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": "+c points out of the face that becomes negative on compression; equivalently it becomes positive on cooling (weis1985 pp. 192-193)"
    },
    "full": [
      [
        [
          0.0,
          -6.81,
          10.0
        ],
        [
          -6.81,
          0.0,
          0.0
        ],
        [
          32.0,
          0.0,
          0.0
        ]
      ],
      [
        [
          -6.81,
          0.0,
          0.0
        ],
        [
          0.0,
          6.81,
          10.0
        ],
        [
          0.0,
          32.0,
          0.0
        ]
      ],
      [
        [
          32.0,
          0.0,
          0.0
        ],
        [
          0.0,
          32.0,
          0.0
        ],
        [
          0.0,
          0.0,
          32.2
        ]
      ]
    ],
    "id": "eo-rT/cln/weis1985",
    "independent": {
      "r13": {
        "notes": "sign explicitly positive in weis1985; Smakula & Claspy 1967 give 10.9",
        "original_reference": "Zook, Chen, Otto, APL 11, 159 (1967)",
        "value": 10.0
      },
      "r22": {
        "notes": "Lenzo et al. 1966 and Smakula 1967 give 6.7",
        "original_reference": "Zook, Chen, Otto, APL 11, 159 (1967)",
        "value": 6.81
      },
      "r33": {
        "notes": "Smakula & Claspy 1967 give 34.0",
        "original_reference": "Zook, Chen, Otto, APL 11, 159 (1967)",
        "value": 32.2
      },
      "r51": {
        "original_reference": "Bernal et al. 1966",
        "value": 32
      }
    },
    "kind": "tensor",
    "name": "Linear electro-optic (Pockels) coefficients, unclamped (constant stress)",
    "notes": "No 1550 nm EO values were found in any source read ( gap 4). Free (T) coefficients vary within +-5% with melt composition (Turner, Nash, Bridenbaugh 1970, via weis1985 p. 199); r22 varies with composition with a minimum near 48.9 mol% (volk2008 p. 150).",
    "provenance": {
      "locator": "Table 4, p. 199",
      "source_id": "weis1985",
      "status": "P-comp",
      "transcribed": "2026-10-25"
    },
    "public": true,
    "rank": 3,
    "scale": 1,
    "symbol": "r^T",
    "symmetry_form": {
      "form": [
        [
          "0",
          "-r22",
          "r13"
        ],
        [
          "0",
          "r22",
          "r13"
        ],
        [
          "0",
          "0",
          "r33"
        ],
        [
          "0",
          "r51",
          "0"
        ],
        [
          "r51",
          "0",
          "0"
        ],
        [
          "-r22",
          "0",
          "0"
        ]
      ],
      "mirror": "x = 0 plane (x perpendicular to the mirror, z polar)",
      "point_group": "3m",
      "relations": [
        "r12 = -r22",
        "r23 = r13",
        "r42 = r51",
        "r61 = -r22"
      ]
    },
    "tensor": "eo-rT",
    "unit": {
      "display": "pm/V",
      "ucum": "pm/V"
    },
    "variant": "cln",
    "variant_note": "composition not stated in weis1985; volk2008 Table 1.2 lists the same values for CLN",
    "voigt": [
      [
        0.0,
        -6.81,
        10.0
      ],
      [
        0.0,
        6.81,
        10.0
      ],
      [
        0.0,
        0.0,
        32.2
      ],
      [
        0.0,
        32.0,
        0.0
      ],
      [
        32.0,
        0.0,
        0.0
      ],
      [
        -6.81,
        0.0,
        0.0
      ]
    ],
    "voigt_convention": {
      "full_from_voigt": "r_ijk = r_Ik, I = V(ij) (impermeability change d(eta)_ij = r_ijk E_k)",
      "order": [
        "xx",
        "yy",
        "zz",
        "yz",
        "xz",
        "xy"
      ],
      "shear_strain": "engineering"
    }
  },
  "recommended_note": null,
  "spread": {
    "r13": {
      "max": 10,
      "min": 10,
      "n_records": 2
    },
    "r22": {
      "max": 7,
      "min": 6.81,
      "n_records": 2
    },
    "r33": {
      "max": 33,
      "min": 32.2,
      "n_records": 2
    },
    "r51": {
      "max": 33,
      "min": 32,
      "n_records": 2
    }
  }
}