The comprehensive approach implemented in this work, which we have initially applied to analyse a relatively short IDP that does not undergo phase separation in vitro, represents a prospecting platform to investigate the conformational ensemble and thermodynamic driving force of other IDPs that exhibit liquid-liquid phase separation under a broad range of solution conditions. Such analysis will provide crucial information at the atomistic level which will be key to unravel biological phase separation in general and assist the design of new building blocks for advanced proteinbased materials and microreactors. the public repository of the PLUMED consortium 126 . We used an exchange frequency of every 500 steps and the acceptance probabilities are between 8-20 %, with the higher acceptance rates mainly for exchanges between high-temperature replicas.