The geometry

First of all we need the *.bas file of the tip and sample geometry (separately). We can use the Jmol to view the *.xyz file. Tip should have tip apex at 0.0 0.0 xy-position. We have even to prepare the Fdata of given properties of elements of tip and sample we will use. For followings we should run the fireball to relax these structures. If you are using new FIREBALL input format, set up followings at the fireball.in file: 

&OPTION
basisfile = <filename>
lvsfile = <filename> 
kptpreference = <filename>
nstepf = 1

Than you have the CHARGES of both the systems tip and sample

The files we need

We need several files before we can simulate the STM scanning for both tip and sample. For sample it is “Atomo_i” with Hamiltonian of the surface and “struc.inp” file with the structure informatioon, hopping file tip_sample_i_j.inp (or interaction_i_j.dat), tip_e_str.inp and tip_g_str.inp with the densities and geometry of the tip respectively.