  Even something as conceptually simple as adsorption of electronegative
adatoms on metal surfaces, where repulsive lateral interactions are expected
for obvious reasons, can lead to unanticipated behavior. In this context, we
explain the origin of surprising lateral interactions between electronegative
adatoms observed on some metal surfaces by means of density functional theory
calculations of four electronegative atoms (N, O, F, Cl) on 70 surfaces of 44
pristine metals. Four different scenarios for lateral interactions are
identified, some of them being unexpected: (i) they are repulsive, which is the
typical case and occurs on almost all transition metals. (ii,iii) They are
atypical, being either attractive or negligible, which occurs on p-block metals
and Mg, and (iv) surface reconstruction stabilizes the low-coverage
configuration, preventing atypical lateral interactions. The last case occurs
predominantly on s-block metals.
