Corrigendum: Models for the computation of opacity of mixtures

Abstract. Equation (4.1) in our paper (2013 New J. Phys. 15 015012) isincorrect. Its corrected version is provided here and justified. It applies to allthe models. 1. Introduction Equation (4.1) in [1] gives the opacity (in cm 2 g −1 ) of a mixture as a linear combination of theopacities of the constituents. It is written there asκ(ρ, T )=1ρX l q l ρ l κ l (ρ l , T ), (4.1)where q l is the number fraction of the element l in the mixture and ρ l is the model-dependent effective density of the latter. 2. Correction The mistake in equation (4.1) stems from the confusion between the real density (hereafter ρ l )and the effective density (hereafter ρˆ l ). The ‘real density’ is an expression of the number ofabsorbing atoms, while the ‘effective density’ describes the physical state (e.g. the ‘size’) ofthe atoms caused by their environment. The latter is model dependent, as shown in [1]. This 1 Author to whom any correspondence should be addressed. Content from this work may be used under the terms of the Creative Commons Attribution 3.0 licence.Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journalcitation and DOI.