We believe that these first two peaks correspond to sites, with the first peak the 'on-top' site and the second the 'bridge' site. This can be seen more explicitly in figure . As with the xTB results in figure the Pt 13 H 2 distribution for H-H interactions is dominated by a single peak corresponding to the single H-H of the GM. Unlike xTB the H-H interaction distance is concentrated in a much smaller distance range. A similar trend is observed for Pt 13 H 4 .