User Tools

Site Tools


dump_tb-hamiltonian_for_stm_simulation

Differences

This shows you the differences between two versions of the page.

Link to this comparison view

Both sides previous revision Previous revision
dump_tb-hamiltonian_for_stm_simulation [2012/05/01 21:27]
jelen
dump_tb-hamiltonian_for_stm_simulation [2012/05/01 21:36]
Line 1: Line 1:
-Let's assume we already obtained fully relaxed atomic and electronic structure of a desired system. To write down Hamiltonian into a file, we will run only one SCF cycle with fixed charges. In addition we need to switch on a flag ''​iwrtatom''​ in section ''&​OUTPUT&''​ in input file ''​fireball in''​. To ensure this, the input file ''​fireball.in''​ should look like: 
- 
- 
-=== fireball.in:​ === 
- 
-<​code>​ 
-&OPTION 
-basisfile = answer.bas ​ 
-nstepf = 1 
-ifixcharge = 1 
-&END 
-&OUTPUT 
-iwrtatom = 1  
-&END 
-</​code>​ 
- 
-The flag ''​iwrtatom''​ can be set to value ''​1''​ or ''​2''​. In case  ''​iwrtatom = 1''​ the Hamiltonian is written in Lowdin orthogonal representation,​ where blocks of Hamiltonian corresponding to each atom and its neighbors are stored to file ''​Atomo_XX'',​ where ''​XX''​ stands for atom number according to list of atoms in ''​*.bas''​ file. If ''​iwrtatom = 2'',​ then the Hamiltonian is written in Atomic Orbital basis set including the overlap matrix. Again 
- 
-Once the ''​iwratom''​ flag is switched on, ''​ dos.optional''​ file is also required. Basically only first line of the file is considered to control, in which units distance will be written (see explanation in the line). 
- 
----- 
- 
-''​dos.optional''​ 
-This file defines basic parameters of the DOS calculation. 
- 
-       ​1.00000 ​             ! ratio of lattice (for fractional coordinates,​ if xyz are in Angstroms maintain 1.000) 
-       ​1 ​  ​60 ​              ! natom_beg,​natom_end (initial and final atom for the DOS calculation) 
-     ​151 ​                   ! number of energies (number of energies in the DOS calcuation) 
-  -10.749617402457092 0.10  ! first energy (initial absolute energy (fireball'​s value is the Fermi Level) and energy step  ​ 
-       ​0 ​                   ! 1/0 yes/no write the tip_e_str.inp file for the DOS 
-      -4.00  4.00           ! minimun and maximum energy limit for writing the green function in the tip_e_str.inp file 
-       ​0.05 ​                ! imaginary part for the green function in the DOS calculation 
- 
----- 
- 
  
dump_tb-hamiltonian_for_stm_simulation.txt ยท Last modified: 2012/05/01 21:36 (external edit)