“…Here, we use the constrained molecular dynamics approach and thermodynamic integration in terms of the blue moon sampling (Ciccotti et al, 2005). This method has been used already by different groups to investigate the stability of metal complexes in aqueous solutions, not only at ambient pressure and temperature conditions (Bühl and Golubnychiy, 2007;Bühl and Grenthe, 2011) but also at hydrothermal (Mei et al, 2013(Mei et al, , 2015(Mei et al, , 2016 and deep crustal high density fluid conditions (Mei et al, 2018).…”