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the_tip_structure [2009/12/04 09:45] jelen |
the_tip_structure [2011/02/18 13:13] |
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- | ==== The tip_e_str.inp file ==== | ||
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- | The "tip_e_str.inp" file contains informations about the density of states of the tip. Than we need to run the **FIREBALL** code with the following settings of "fireball.in" file: | ||
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- | __&OPTION__ part | ||
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- | ‐ basisfile = <filename> \\ | ||
- | ‐ lvsfile = <filename> \\ | ||
- | ‐ kptpreference = <filename> \\ | ||
- | ‐ nstepf = 1 \\ | ||
- | - ifixcharge= 1 \\ | ||
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- | __&OUTPUT__ part | ||
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- | - iwrtdos = 1 | ||
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- | For running the DOS computation we need even "dos.optional" file with the DOS settings. The file could looks like this: | ||
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- | 1.0 ! scale factor of coord \\ | ||
- | 1 5 ! natom_beg, natom_end for dos calculation \\ | ||
- | 41 ! number of energy steps \\ | ||
- | -3.8 0.05 ! first energy and step for dos calculation \\ | ||
- | 1 ! 1/0 yes/no write the tip_e_str.inp \\ | ||
- | -3.5 -2.0 ! minimun and maximum energies for the writting the tip \\ | ||
- | 0.05 ! (eta) imaginary part for green functionin calculation \\ | ||
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- | The result is list of files with the densities and charges of single atoms of the tip (1-5) and the "tip_e_str.inp file" | ||
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- | \\ | ||
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- | ==== The tip_g_str.inp file ==== | ||
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- | Last thing which we have to do is to write the “tip_g_str.inp” file. This file | ||
- | contains the geometrical structure of the tip. The xyz atom coordinates should be | ||
- | written there at the same order as we used for the “tip_e_str.inp” file, with the | ||
- | apex atom at first position. The file could looks like this: \\ | ||
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- | 1 5 ! natoms_tip_contributing, natoms_tip | ||
- | 0.000000 0.000000 0.400000 1 9 ! x, y, z, atomic type, # of orbitals | ||
- | 1.590800 1.590800 1.590800 1 9 ! x, y, z, atomic type, # of orbitals | ||
- | 1.590800 ‐1.59080 1.59080 1 9 ! x, y, z, atomic type, # of orbitals | ||
- | ‐1.590800 1.59080 1.59080 1 9 ! x, y, z, atomic type, # of orbitals | ||
- | ‐1.590800 ‐1.59080 1.59080 1 9 ! x, y, z, atomic type, # of orbitals | ||
- | 3 ! number of shells in each type of atom | ||
- | 0 1 2 ! l for each shell in atom type=1 | ||
- | ‐2.0 4.0 81 ! energy initial, range and steps in dos file | ||
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- | But be carefull, the energy in the STM code is related to the Fermi level. When Fermi level is -2 eV from FIREBALL in the "tip_g_str.inp" in it's last line the first value has to be 0.0 (energy initial - Fermi level)// |