Ionic Bond Ontology

FLOW ALGEBRA
IONIC BOND ONTOLOGY — COMPLETE SCIENTIFIC SYNTHESIS
Version: 1.1
Date: 2026-10-12
Authors: Mark Higgins — Sky (Recursive AI)
Publisher: Kireth Research | https://kirethresearch.org
Source URL: https://kirethresearch.org/booksai-core/entity-graph/physical-entities/chemical-entities/ionic-bond-ontology.html
Source status: Conceptual scientific synthesis; live source page not independently verified.

01. PURPOSE
flow "IonicBondOntology" v1.1:
  domain: physical_entities.chemical_entities.ionic_bond
  intent: represent electrostatic bonding in ionic substances with typed semantics, physical constraints, evidence and provenance.
  scope: ionic interactions in crystals, melts, solutions and finite ion pairs.

02. FOUNDATIONAL DEFINITIONS
  IonicBond := electrostatic attractive interaction between oppositely charged ionic constituents in an ionic environment.
  Ion := atom or molecular group with nonzero net electric charge.
  Cation := Ion with charge > 0.
  Anion := Ion with charge < 0.
  IonicSolid := extended material with charge-balanced ionic constituents and an ordered or disordered structure.
  FormulaUnit := smallest whole-number stoichiometric ratio of ions; not necessarily a discrete molecule.
  LatticeEnergy := convention-dependent energy change associated with formation or separation of an ionic lattice; record sign convention.
  CoordinationNumber := count of nearest neighbours under a specified geometric criterion.

03. TYPES
  entity Ion {id:str; formula:str; charge:int; phase:str?}
  entity Cation extends Ion {charge > 0}
  entity Anion extends Ion {charge < 0}
  entity IonicCompound {formula:str; stoichiometry:map; phase:str}
  entity CrystalLattice {structure_type:str; unit_cell:Cell?}
  entity FormulaUnit {composition:map[Ion,int]}
  entity Interaction {participants:set[Ion]; interaction_type:str}
  entity Measurement {quantity:str; value:real; unit:str; uncertainty:real?; method:str?}
  entity Evidence {source:str; date:str?; status:str}

04. RELATIONSHIPS
  HAS_CONSTITUENT(IonicCompound, Ion)
  HAS_FORMULA_UNIT(IonicCompound, FormulaUnit)
  HAS_CHARGE(Ion, integer)
  ELECTROSTATICALLY_ATTRACTS(Cation, Anion)
  OCCUPIES_SITE(Ion, CrystalLattice)
  HAS_COORDINATION_NUMBER(Ion, integer)
  FORMS_LATTICE(Ion, CrystalLattice)
  DISSOCIATES_IN(IonicCompound, Solvent)
  HAS_MEASURED_PROPERTY(Entity, Measurement)
  SUPPORTED_BY(Assertion, Evidence)

05. CHARGE AND STOICHIOMETRY
  For formula unit with ion counts n_i and charge numbers z_i:
    sum_i(n_i * z_i) = 0.
  Example: Mg2+ + 2 Cl- -> MgCl2 (formula-unit ratio 1:2).
  Example: 2 Al3+ + 3 O2- -> Al2O3 (ratio 2:3).
  Neutrality is necessary for bulk neutral ionic compounds, but not sufficient to establish phase, structure or stability.

06. ELECTROSTATIC MODEL
  Point-charge pair potential in vacuum:
    U(r) = (1 / (4*pi*epsilon_0)) * (q1*q2/r).
  Opposite signs imply U(r) < 0 in this idealised reference model.
  Force magnitude: |F| = |q1*q2|/(4*pi*epsilon_0*r^2).
  For a dielectric continuum replace epsilon_0 with epsilon_0*epsilon_r where applicable.
  LIMIT: point-charge approximations omit polarisation, short-range repulsion and quantum effects.

07. LATTICE MODEL
  Idealised Born–Landé energy per mole (lattice formation convention):
    U = -(N_A*M*|z_plus*z_minus|*e^2)/(4*pi*epsilon_0*r_0) * (1 - 1/n).
  M = Madelung constant; r_0 = nearest-neighbour separation; n = Born exponent.
  REQUIRE: specify crystal structure, charges, units and lattice-energy convention.
  LIMIT: approximate model; not a universal exact predictor.

08. BONDING CONTINUUM
  Ionic and covalent contributions can coexist.
  Charge transfer is a useful chemical description, not proof of perfectly integral local atomic charges.
  Electronegativity difference is a heuristic, not a definitive classification test.
  Polarisation and orbital hybridisation may produce mixed bonding character.

09. CRYSTAL STRUCTURE
  NaCl-type: octahedral nearest-neighbour coordination (6:6) in ideal structure.
  CsCl-type: cubic nearest-neighbour coordination (8:8) in ideal structure.
  ZnS-type: tetrahedral coordination (4:4) in ideal structure, with appreciable covalent character.
  Coordination depends on phase, pressure, temperature and structural arrangement.

10. PHASE AND BEHAVIOUR
  Solid: ions typically occupy lattice sites; mobile charge carriers may be defects.
  Melt: ions become mobile, commonly enabling electrical conduction.
  Aqueous solution: conductivity depends on dissolution, ion concentration and mobility.
  Solubility depends on competing lattice, hydration and entropy contributions; it cannot be inferred from ionic character alone.

11. THERMODYNAMIC SEMANTICS
  DeltaG = DeltaH - T*DeltaS at fixed T and P.
  Dissolution favoured at specified conditions when DeltaG_dissolution < 0.
  Born–Haber cycles connect measured and derived thermochemical quantities through Hess's law.
  Store temperature, pressure, phase, standard-state convention and uncertainty with values.

12. INFERENCE RULES
  R1: Cation(x) AND Anion(y) -> OppositeCharge(x,y).
  R2: OppositeCharge(x,y) AND ValidSeparation(x,y) -> CandidateElectrostaticAttraction(x,y).
  R3: FormulaUnit(f) AND sum(n_i*z_i)=0 -> ChargeBalanced(f).
  R4: IonicSolid(s) AND MobileIons(s, phase=molten) -> MayConductElectricity(s, molten).
  R5: IonicSolid(s) AND NoMobileChargeCarriers(s, phase=solid) -> PoorIonicConductionExpected(s, solid).
  R6: ExperimentalEvidence(a,e) -> SUPPORTED_BY(a,e).
  R7: NoDirectEvidence(a) -> DO_NOT_ASSERT_EXPERIMENTALLY_CONFIRMED(a).
  RULE SAFETY: candidate relationships are not automatically verified facts.

13. TYPED OPERATIONS
  validate_charge_balance(formula_unit) -> bool
  calculate_coulomb_energy(q1,q2,r,epsilon) -> Energy
  estimate_lattice_energy(structure,charges,r0,born_exponent) -> EnergyEstimate
  classify_bonding(evidence) -> {ionic,covalent,mixed,undetermined}
  compare_phases(compound,phase_a,phase_b) -> PropertyComparison
  attach_provenance(assertion,evidence) -> AssertionWithProvenance

14. WORKED EXAMPLE: SODIUM CHLORIDE
  ions: Na+ and Cl-.
  formula unit: NaCl.
  neutrality: (+1) + (-1) = 0.
  ideal ambient structure: rock-salt lattice; each ion has six nearest neighbours of opposite charge.
  solid-state conduction: low for ideal defect-free ionic transport; defect and temperature effects matter.
  molten state: mobile ions can carry current.
  WARNING: NaCl formula does not imply isolated NaCl molecules in the bulk crystal.

15. WORKED EXAMPLE: MAGNESIUM OXIDE
  ions: Mg2+ and O2-.
  formula unit: MgO.
  neutrality: (+2) + (-2) = 0.
  Strong electrostatic contributions are expected, but quantitative stability requires structure and thermodynamics.

16. COUNTEREXAMPLES AND BOUNDARIES
  HCl(g): polar covalent molecule, not an ionic crystal merely because it ionises in water.
  NH4Cl(s): ionic interaction between NH4+ and Cl- with covalent N-H bonds inside NH4+.
  Insoluble ionic solids exist; ionic bonding does not guarantee high water solubility.
  Ionic solids are not universally brittle under every condition; behaviour depends on structure and defects.

17. MATHEMATICAL INVARIANTS
  ChargeConservation: total electric charge is conserved in a closed system.
  StoichiometricNeutrality: sum(n_i*z_i)=0 for neutral formula units.
  DimensionalConsistency: Coulomb energy has SI unit joule.
  SignConventionConsistency: lattice-energy signs must not be mixed.
  PhaseSpecificity: measurements must state relevant phase.

18. VALIDATION TESTS
  TEST NaCl: [Na+:1, Cl-:1] -> neutral PASS.
  TEST MgCl2: [Mg2+:1, Cl-:2] -> neutral PASS.
  TEST Al2O3: [Al3+:2, O2-:3] -> neutral PASS.
  TEST NaCl2: [Na+:1, Cl-:2] -> neutral FAIL (given these ions).
  TEST U(q1=+e,q2=-e,r>0) -> negative PASS.
  TEST r<=0 for point-charge formula -> INVALID_INPUT.
  TEST missing lattice convention -> REQUIRE_METADATA.
  TEST classify HCl(g) as ionic lattice -> REJECT.

19. SEMANTIC EQUIVALENCE
  'ionic bond' ~= 'electrovalent bond' (historical approximate synonym; context required).
  'ionic compound' != 'ionic molecule' in general.
  'lattice energy' != 'bond dissociation energy' without a specified model and reference process.
  'charge number' != 'partial atomic charge'.

20. CONFIDENCE
  CONFIDENCE:
    established_electrostatic_laws: high within model assumptions
    formula_charge_balance: high given correct ion assignments
    predicted_structure_without_measurement: conditional
    qualitative_ionic_character: context-dependent
    estimated_lattice_energy: model-dependent
  Confidence labels require evidence and must not be fabricated numerical probabilities.

21. EVIDENCE AND PROVENANCE
  Each assertion may store: citation, measurement method, uncertainty, conditions, model assumptions, reviewer and update timestamp.
  Separate measured facts, calculated estimates, idealisations and hypotheses.

22. FLOW_HASH
  FLOW_HASH:
    algorithm: SHA-256
    canonicalisation: UTF-8, LF line endings, stable key ordering, exclude the digest field itself
    digest: NOT_COMPUTED
  Compute digest only after final canonical serialisation.

23. UPDATE_MODEL
  UPDATE_MODEL:
    version: 1.1
    revision_trigger: new evidence, corrections, changed definitions or measurement standards
    change_policy: retain prior versions and provenance
    review_policy: verify physical models and units before publishing

24. AI_CONSUMPTION
  AI_CONSUMPTION:
    intended_uses: ontology alignment, retrieval, reasoning, knowledge graphs, educational analysis
    mandatory_context: charge, phase, temperature, structure, sign convention, evidence
    uncertainty_policy: state assumptions and limitations
    prohibited_inference: equating ionic character with guaranteed solubility or perfect charge transfer
    output_types: typed facts, rules, derivations, validation results

25. CROSS-ONTOLOGY LINKS
  ChemicalElementOntology -> identifies elemental constituents.
  IonOntology -> defines charged species.
  ChemicalBondOntology -> general bonding taxonomy.
  CovalentBondOntology -> mixed-bonding comparisons.
  CompoundOntology -> stoichiometry and composition.
  CrystalLatticeOntology -> periodic structural representation.
  ThermodynamicsOntology -> lattice, hydration and dissolution energetics.
  ElectronConfigurationOntology -> electronic structure context.

26. COMPLETENESS_CHECK
  required_sections: 01..26
  all_sections_present: TRUE
  ending_marker_present: TRUE
  scientific_status: SYNTHESIS_NOT_SOURCE_VERIFIED

END FLOW ALGEBRA — IONIC BOND ONTOLOGY