# Tag Info

## Hot answers tagged transport

13

They do not have an easy interface, however, there are some tutorials and examples that can be used, you can use as an input parameter: github.com/siesta-project/tutorials. The input file is in .fdf, you can try to generate only the structure through nanolab> 2015 with commercial or academic version. But the calculator will always be set manually, with ...

12

This is not the exact response to your question, but I would like to present a very good youtube channel QuantumNerd. Its content is vast and interesting, concerning materials simulation. Recently, he posted a video about a project of making multi-platform GUI for Quantum ESPRESSO, he mentioned though the possibility of growing the project to other DFT ...

7

The general answer to your question is that it depends on what scientific question you are wanting to answer. However, since you're interested in thermoelectric properties, the material you're studying is probably a semiconductor and has a band-gap. This means that the conductivity is essentially zero unless you dope it, so using the undoped Fermi energy ...

7

GUI4dft - A SIESTA oriented GUI GUI4dft is a new Graphical User Interface for Density Functional Theory for users of SIESTA. GUI4dft is written in Python language, falls under an MIT license and is a free cross-platform software. GUI4dft allows the user to work with standard SIESTA files and prepare manuscript-quality figures of the atomic structure and ...

7

Whatever scattering mechanism you choose must respect detailed balance in equilibrium: on average, the number of particles hitting a patch of the wall at a given angle and velocity must equal the number of particles reflected at the same angle and velocity. If this were not the case, the system would not be in equilibrium. There are numerous ways to do this ...

7

Nanodcal Nanodcal is implemented with real space density functional theory (DFT) using the Keldysh nonequilibrium Green’s function formalism (NEGF). It can calculate nonlinear and non-equilibrium quantum transport properties of two-probe open device structures. The software uses linear combination of atomic orbitals (LCAO) to expand physical quantities and ...

6

TranSIESTA (SIESTA) TranSIESTA is an LCAO code (similar to OpenMX) which is implemented in fortran. The NEGF methods here allows N>=1 -terminal calculations as well as real space self-energies (for single device/defect calculations). It is open source.

6

OpenMX OpenMX is another LCAO code (similar to SIESTA) which is implemented in C. It also implements the NEGF formalism similar to TranSiesta. It is open source.

6

Siesta relies on the LCAO method which is different from the plane wave (PW) formalism encountered in the VASP and QE codes. A noteworthy difference between the two types of methods is the convergence of precision. In PW there is basically a single value (the plane-wave cutoff) that you simply increase to improve precision. In LCAO the basis set is more ...

5

I provide more information about the tools for quantum transport. KITE KITE is an open-source Python/C++ software suite for real-space tight-binding (TB) simulations of electronic structure and bulk quantum transport properties of disordered systems scalable to multi-billions of atomic orbitals. Kwant Kwant is a free (open source), powerful, and easy to use ...

5

Since no one has responded with expertise, I'll attempt a speculative answer here. To my mind, the simplest model of the atoms on the surface of the walls would be an ensemble of independent classical 3D harmonic oscillators at some temperatures $T_{\rm wall}$. That would be pretty easy to describe from a numerical standpoint, since their velocity could be ...

2

I strongly suggest that you start from simple calculations instead going directly for transport calculations. Transport calculation in SIESTA are tricky: you have to define the electrodes, the main region, run optimization calculations for each one, match all of them and finally, do the transport calculation. In the SIESTA page, you can find links for ...

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