Liquid vs. Solid Cu. With this reference established for the liquid metal surface, we can now compare the "gap" reported at both liquid and solid Cu. The inflection-point gap on Cu(111) was previously measured at room temperature via ex situ total-reflection high-energy positron diffraction (TRHEPD) and atomic force microscopy (AFM) as 2.34 ± 0.06 Å and 2.0 ± 0.2 Å , respectively (corresponding to a direct "gap" of 3.34 ± 0.06 Å and 3.0 ± 0.2 Å). Unfortunately, the large scatter between these two experimental values and their inherent uncertainty renders it impossible to draw any conclusions on a difference between the "gap" at solid and liquid Cu. Such a difference could be potentially induced by a more considerable dynamic buckling of Gr on liquid Cu that gives rise to a somewhat stronger sp 3 activation of Gr and a concomitant chemical interaction in addition to the dispersive interaction known to dominate the binding of Gr on solid Cu(111). To this end, we resort to an MTP@PBE+MBD based computation, which we conduct in the gigantic minimal-strain c(27 x 27√3) simulation cell for reasons apparent below. The resulting value for the "gap" on Cu(111) at 300K is 2.259 (±0.0002) Å (see Table and ), i.e., about 0.14 Å larger than the "gap" computed at liquid Cu at 1370K . While this difference could indeed reflect an additional chemical interaction at the liquid Cu catalyst, it could also merely be the result of anharmonic vibrations at the differing temperatures (300K vs. 1370K). Therefore, we proceed to compute the Gr gap on solid and liquid Cu at the same elevated, but a slightly reduced temperature of 1200K compared to the Cu melting point, respectively. This temperature is chosen since it is close to the estimated melting point of PBE-DFT , and we here exploit that on MD timescales of 1 ns, the melting of the solid or freezing of the liquid does not yet set in for the employed simulation cells (compare Figure ) and the simulation of Gr-Cu(l) corresponds to a supercooled state. These simulations yield inflection-point "gaps" of 2.121 ± 0.002 Å and 2.165 ± 0.004 Å, for liquid and solid Cu, respectively (see also Figure ). They are thus virtually identical at the same temperature (∆ = 0.044 Å), which suggests an essentially identical nature of the bonding at both solid and liquid Cu that is predominantly dispersive. In addition, this interpretation is corroborated by highly similar adsorption energies of -48 meV/atom on liquid vs. -40 meV/atom on solid Cu(111) at 1200K , as well as highly similar dband center positions as a ruling descriptor for chemisorptive interactions . The typical neighboring environments with negative and positive 𝛿𝜃 are shown by insets. Note that the probability densities show only marginal differences for free Gr, as well as Gr on liquid (Gr-Cu(l)) and solid Cu (Gr-Cu(111)). (b) The difference between the distributions of 𝛿𝜃 and 𝜃 with respect to freestanding Gr.