Fig. 3

Fourier components at these tip separations. Fourier transforms of IOA p4mm wave functions with (b times) an STM tip half-separation a bu = 0, b bu = 0.6, c bu = 0.74, and d bu = 0.77 = π/4 − ε units in the horizontal direction, relative to the IOA p4mm surface wave functions having a period of 2π. Reciprocal lattice vectors {1,0} and {0,1} (= {H,K}) are marked in (a)