Overview
EN ISO 80000-12:2019 (Quantities and units - Part 12: Condensed matter physics) is the CEN-endorsed edition of ISO 80000‑12 that specifies names, symbols, definitions and units for quantities used in condensed matter physics. Where appropriate, conversion factors and conventional non‑SI units (for example the ångström, Å, used in crystallography) are noted. This corrected version (ISO 80000‑12:2019, corrected 2021‑11) aligns with other parts of the ISO 80000 series and supports consistent notation across research, industry and standards documents.
Key topics
The standard organizes quantities and units in a comprehensive table (Table 1) and includes an annex on crystal planes and directions. Important topics and defined quantities include:
- Lattice and reciprocal lattice: lattice vectors, fundamental translation vectors and reciprocal‑lattice vectors (including 2π conventions used in crystallography).
- Diffraction & scattering: lattice plane spacing (d), Bragg angle (formula 2d sinϑ = nλ), atomic scattering factor and structure factor.
- Vibrational properties: Debye angular frequency ωD, Debye temperature (ΘD = ħωD / k), density of vibrational states and Debye angular wavenumber qD.
- Electronic quantities: angular wavenumber (k), Fermi wavenumber, energy density and density of electronic states.
- Defects & transport: Burgers vector, displacement vectors, mean free path (phonons/electrons), residual resistivity ρ0 and Lorenz coefficient.
- Thermodynamic and elastic parameters: Grüneisen parameter (thermodynamic and mode‑specific definitions), Debye‑Waller factor and related reductions in diffraction intensity.
Practical applications
EN ISO 80000‑12:2019 is used to:
- Standardize notation and units in research papers, textbooks and technical reports in condensed matter physics and materials science.
- Ensure consistent parameter naming in simulation packages, data exchange formats and laboratory information management systems (LIMS).
- Support metrology, instrumentation and calibration where quantities such as lattice spacing, phonon spectra, electronic density of states and transport coefficients are reported.
- Guide crystallographers, solid‑state physicists, materials engineers, metrologists and standards writers in choosing unambiguous symbols and units.
Who should use this standard
- Academic and industrial condensed matter physicists and crystallographers
- Materials scientists and nanotechnology researchers
- Software developers for simulation and data‑analysis tools
- Standards committees, technical editors and journal publishers
- Metrology laboratories and instrumentation manufacturers
Related standards
- Other parts of the ISO 80000 series (for base units and related quantities, e.g., ISO 80000‑1, ‑3, ‑4, ‑5, ‑7)
- IEC/ISO joint work on quantities and units and relevant national standards adopted via CEN
Using EN ISO 80000‑12:2019 improves clarity, interoperability and scientific reproducibility by providing a single reference for quantities, symbols and units in condensed matter physics.
