Electronic structure of interstitial impurity systems Fe-X (X = Li, Be
, B, C, N, O and F) is calculated and location-relaxation two-dimensio
nal binding surfaces are constructed in order to elucidate the locatio
n and dynamics of these impurities. The results indicate that Li, Be a
nd F favor the tetrahedral interstitial site whereas B, C and N favor
the octahedral site.