Source: https://guthlabs.ai/docs/instruments/electronegativity-difference-bond-type-predictor/implementation/

instrument implementation / implementation-contract

# Electronegativity Difference / Bond Type Predictor implementation

A source-bound implementation contract for Electronegativity Difference / Bond Type Predictor; deployment and executable qualification remain separate.

Status: **VERIFIED_CLEAN**Lifecycle: **implementation-contract**

## Binding contract

This record describes what an executable surface must bind and validate. It does not claim that a public calculator, package, or production route is deployed.

**Record owner**: Guth Instruments

**Lifecycle**: verified-clean

**Evidence ID**: t6-127

**Effect**: Computation or source lookup only

## Input and validation requirements

- Elements without a standard or agreed Pauling electronegativity value, including some noble gases and certain less-common elements, need an explicit unsupported-input behavior.

- A missing lookup value must not silently become zero or produce NaN; the instrument should return a clear unavailable-data error.

- The same element should normally produce ΔEN = 0 and nonpolar covalent under this rule, although actual bonding context can still matter.

- Rounded lookup values can move a result across a threshold, especially near ΔEN = 0.5 or 1.7.

- The lookup table version, values, and precision must be fixed and exposed for reproducibility.

- No division-by-zero hazard exists in the stated formula.

## Required corrections

No binding erratum is attached to this unique-name record. Implementers must still preserve the declared units, domain, and failure behavior.

## Inspectable interface fixture

The sample below is evidence for interface and validation tests, not a production implementation.

````
{
  "inputs": {
    "element_A": "O",
    "element_B": "O",
    "EN_A_Pauling": 3.44,
    "EN_B_Pauling": 3.44
  },
  "expected_outputs": {
    "delta_EN": 0,
    "predicted_bond_type": "nonpolar covalent"
  },
  "working": "ΔEN = |3.44 − 3.44| = |0.00| = 0.00. Since 0.00 < 0.5, the rule predicts nonpolar covalent. This is the zero-difference edge case."
}
````

## Other records

[01**Overview**](<https://guthlabs.ai/docs/instruments/electronegativity-difference-bond-type-predictor/>)[02**Mechanism**](<https://guthlabs.ai/docs/instruments/electronegativity-difference-bond-type-predictor/mechanism/>)[04**Qualification**](<https://guthlabs.ai/docs/instruments/electronegativity-difference-bond-type-predictor/qualification/>)

## Sources and evidence

These pointers bind the page to evidence. They do not grant authority or collapse verification into deployment.

- `VERIFIED_LEDGER.json`

- `evidence-tranche6/tranche6-results.json`