First-principles calculations are used to rationalize the formation of well-separated $\left(\sim 10\text{Å}\right)$ molecular rows of phenylglycine upon coadsorption of adenine and phenylglycine on Cu(110) [Q. Chen and N. V. Richardson, Nat. Mater. 2, 324 (2003)]. It is found that the molecular adsorption leads to long-wave oscillations of the charge density at the Cu(110) surface. The experimentally observed indirect interaction between the molecular rows is mediated by these charge fluctuations. Strain effects, in contrast, are of minor importance.

• Received 3 December 2008

DOI:https://doi.org/10.1103/PhysRevB.78.233411