Source: https://guthlabs.ai/docs/instruments/empirical-molecular-formula-finder/implementation/

instrument implementation / implementation-contract

# Empirical & Molecular Formula Finder implementation

A source-bound implementation contract for Empirical & Molecular Formula Finder; 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**: live-source boundary

**Effect**: Computation or source lookup only

## Input and validation requirements

A zero-mass element produces a zero smallest-mole value and therefore undefined normalization; the instrument must reject it. Unit interpretation of molecular molar mass can also change the molecular formula by a factor of 1000 if not explicitly constrained.

## 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": {
    "composition_type": "percent",
    "percent_composition": {
      "C": 40,
      "H": 6.71,
      "O": 53.29
    },
    "atomic_weights": {
      "C": 12.011,
      "H": 1.008,
      "O": 15.999
    },
    "molecular_molar_mass_g_per_mol": 180.156
  },
  "expected_outputs": {
    "empirical_formula": "CH2O",
    "molecular_formula": "C6H12O6",
    "ratio_table": {
      "C": 1,
      "H": 1.999,
      "O": 1
    },
    "empirical_molar_mass_g_per_mol": 30.026,
    "molecular_multiplier": 6
  },
  "working": "Use a 100 g basis: C moles = 40.00/12.011 = 3.33028; H moles = 6.71/1.008 = 6.65675; O moles = 53.29/15.999 = 3.33083. Divide by the smallest value, 3.33028: C = 1.00000; H = 6.65675/3.33028 = 1.99886, approximately 2; O = 3.33083/3.33028 = 1.00017, approximately 1. Empirical formula = CH2O. Empirical mass = 12.011 + (2 x 1.008) + 15.999 = 30.026 g/mol. Molecular multiplier = 180.156/30.026 = 6. Molecular formula = C6H12O6."
}
````

## Other records

[01**Overview**](<https://guthlabs.ai/docs/instruments/empirical-molecular-formula-finder/>)[02**Mechanism**](<https://guthlabs.ai/docs/instruments/empirical-molecular-formula-finder/mechanism/>)[04**Qualification**](<https://guthlabs.ai/docs/instruments/empirical-molecular-formula-finder/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-tranche2/batch10-output.jsonl`