\\
==== 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.