At 200 K, the fraction of terrace diffusion rises to 42 % (Na) and 36 % (Li). The higher temperature facilitates overcoming the kinetic hindrance of detachment processes from individual adatoms onto the terrace. In this way, individual atoms can be interchanged more For entries labelled with "(hop.)", only hopping processes were considered during the kMC simulation. In the case of Na(100), the graph of " 1 /2 ML" is overlapped by " 1 /8 ML (hop.)". The corresponding diffusion coefficients are given in Table .