\\
==== 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__ part

‐ 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 files" with the structure informatioon, hopping file
“tip_sample_i_j.inp” (“interaction_i_j.dat”), “tip_e_str.inp” and “tip_g_str.inp” with
the densities and geometry of the tip respectively.