wavenumber in medium

symbol: σ, units: m−1, cm−1
synonym: wavenumber
https://doi.org/10.1351/goldbook.08301
Reciprocal of wavelength of electromagnetic radiation. σ=1/λ.
Notes:
  1. In spectroscopy, the unqualified term 'wavenumber' (sometimes referred to as "reciprocal centimetre" cm−1) often means vacuum wavenumber, and symbol σ often means ν~.
  2. SI unit: m−1. Common unit: cm−1.
Source:
PAC, 2021, 93, 647. (Glossary of methods and terms used in analytical spectroscopy (IUPAC Recommendations 2019)) on page 678 [Terms] [Paper]
Citation: 'wavenumber in medium' in IUPAC Compendium of Chemical Terminology, 5th ed. International Union of Pure and Applied Chemistry; 2025. Online version 5.0.0, 2025. https://doi.org/10.1351/goldbook.08301 RIS BibTex EndNote
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