Raw, as measured, Raman spectra and the modified MCR routine used in the work described in the following article. Mukherjee, T.; Smith, E. K.; Sulpizi, M.; Rabe, M. Hydration shell water surrounding citrate-stabilised gold nanoparticles. Nanoscale 2025, 17 (26), 15772–15784. https://doi.org/10.1039/D5NR01153A. The MCR code was modified from pyMCR version 0.5.2 (https://doi.org/10.18434/M32064). Camp, C. H. pyMCR: A Python Library for Multivariate Curve Resolution Analysis with Alternating Regression (MCR-AR). J. Res. Natl. Inst. Stand. Technol. 2019, 124, 124018. https://doi.org/10.6028/jres.124.018.