STM image of Si(111) 7x7 reconstruction This is the first image taken of the Si 7x7 recontruction at OU. An atomic step edge is clearly visible along the upper 1/3 of the 21x21 nm2 image. Tunneling conditions: sample bias 2.2 V and tunneling current 0.6 nA. The color scale range is 0.92 nm.