In order to better characterize the dynamics of the citrates, unveiling their intrinsic diversity, we applied a data-driven approach to identify the different molecular states populated by the anionic species, akin to the analysis reported in our previous study on interacting TMA-Au NPs. The approach is based on the usage of Smooth Overlap of Atomic Positions (SOAP) -high-dimensional descriptors that classify the molecular arrangement of each molecule by encoding its atomic/molecular environment. Here, we compute the SOAP descriptor associated to the centre of mass of each citrate ion by defining its molecular state by examining the position of all the surrounding citrates. We performed the SOAP analysis using the Python package DScribe, 87 using rcut = 65 Å, nmax = 8 Å, lmax = 8 Å.