Scanning Tunneling Microscopy (STM) is a widely used experimental technique. STM maps out a convolution of the geometric and electronic structure of a given surface and it is often difficult if not impossiple to intrepret STM images without the aid of theoretical tools.
We will use GPAW to simulate an STM image. Start by doing an Al(100)
surface with hydrogen adsorbed in the ontop site:
HAl100.py. This will produce a
gpw file containing the wave functions that are needed for
calculating local density of states.
The STM image can be calculated with the stm.py script:
$ python3 stm.py HAl100.gpw
Try the following:
- clean slab without hydrogen
- different number of layers
- different number of k-points
- different current
- negative bias (positive tip)