Drude–Nernst equation (for electrostriction) 

https://doi.org/10.1351/goldbook.DT07364
Equation describing the contraction (ΔVel) taking place in a dielectric medium of relative static permittivity εr (formerly called dielectric constant) upon introduction of an ion of charge number z and radius r: ΔVel=−(ze)22rεr∂(lnεr)∂p with e the elementary charge.
Note:
Inasmuch as the derivative of lnεr with respect to pressure, ∂(lnεr)∂p, is not known for all media, there are approximations to evaluate this term as a function of εr and of the isothermal compressibility of the medium, κT.
Source:
PAC, 2007, 79, 293. (Glossary of terms used in photochemistry, 3rd edition (IUPAC Recommendations 2006)) on page 327 [Terms] [Paper]
Citation: 'Drude–Nernst equation (for electrostriction)' 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.DT07364 RIS BibTex EndNote
Div. IIIPDFTextXMLJSON
Last revised: February 24, 2014