Conventions, Symbols, Quantities, Units and Constants for High Resolution Molecular Spectroscopy J. Stohner, M. Quack ETH Zürich, Laboratory of Physical Chemistry, Wolfgang-Pauli-Str. 10, CH-8093 Zürich, Switzerland, Email:
[email protected] reprinted from “Handbook of High-Resolution Spectroscopy”, Vol. 1, chapter 5, pages 263–324 M. Quack, and F. Merkt, Eds. Wiley Chichester, 2011, ISBN-13: 978-0-470-06653-9. Online ISBN: 9780470749593, DOI: 10.1002/9780470749593 with compliments from Professor Martin Quack, ETH Zürich Abstract A summary of conventions, symbols, quantities, units, and constants which are important for high-resolution molecular spectroscopy is provided. In particular, great care is taken to provide definitions which are consistent with the recommendations of the IUPAC “Green Book”, from which large parts of this article are drawn. While the recommendations in general refer to the SI (Système International), the relation to other systems and recommendations, which are frequently used in spectroscopy, for instance atomic units, is also provided. A brief discussion of quantity calculus is provided as well as an up-to-date set of fundamental constants and conversion factors together with a discussion of conventions used in reporting uncertainty of experimentally derived quantities. The article thus should provide an ideal compendium of many quantities of practical importance in high-resolution spectroscopy. Keywords: conventions; symbols; quantities; units; fundamental constants; high-resolution spectroscopy; quantity calculus; reporting uncertainty in measured quantities; IUPAC Conventions, Symbols, Quantities, Units and Constants for High-resolution Molecular Spectroscopy Jurgen¨ Stohner1,2 and Martin Quack2 1ICBC Institute of Chemistry & Biological Chemistry, ZHAW Z¨urich University of Applied Sciences, W¨adenswil, Switzerland 2Laboratorium f¨ur Physikalische Chemie, ETH Z¨urich, Z¨urich,Switzerland 1 INTRODUCTION metric units of Newton (force)-seconds (N-s).