SIESTA is both a method and its computer program implementation, to perform efficient electronic structure calculations and ab initio molecular dynamics of molecules and solids. SIESTA is under continuous development since it was first published and is currently used by thousands of scientists worldwide. Its original and innovative approach, able to handle large scale systems, has even inspired the development of other atomistic codes.

The backronym of SIESTA is Spanish Initivative for Electronic Simulations with Thousands of Atoms.


SIESTA atomistic properties


Main characteristics:

  • SIESTA was born as a collaborative project
  • SIESTA is in continuous development since it was implemented
  • SIESTA has become very popular, being increasingly used by researchers in geosciences, biology and engineering (apart from those in its natural habitat of materials physics and chemistry)




The SIESTA Team are authors of one of the 12 most important papers in history of the Journal of Physics.



The SIESTA method for ab initio order -N materials simulation, J. M. Soler, E. Artacho, J.D. Gale, A. García, J. Junquera, P. Ordejón and D. Sánchez-Portal, J. Phys.: Condens. Matter 14 2745 (2002), receives more than 800 citations/year.

"Density-functional method for nonequilibrium electron transport", M. Brandbyge, J.L. Mozos, P. Ordejón, J. Taylor, and K. Stokbro, Phys. Rev. B, 65, 165401 (2002) (Included in SIESTA 4.0)

"Improvements on non-equilibrium and transport Green function techniques: The next-generation tranSIESTA", N. Papior, N. Lorente, T. Frederiksen, A. García and M. Brandbyge, Computer Physics Communications, 212, 2017 (Included in SIESTA 4.1)


open source code with professional support and warranty

SIMUNE provides official support for a professional use of SIESTA.

SIMUNE has received funds to develop the project: SIESTA -PRO - Spanish Initiative for Electronic Simulatinons with Thousands of Atoms: Open Source code with professional support and warranty. The project (RTC-2016-5681-7) has been funded by the Spanish Ministry of Economy, Industry and Competitiveness and has been co-financed by the European Structural and Investment Funds with the objective to promote the technological development, innovation and quality research.


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NEW LICENSE (announced on 13th May 2016)

The SIESTA developers have decided to change the licensing conditions for the code. From now on, SIESTA will be released under the GPL open-source license.


In the past, SIESTA had always been free for academic use, but re-distribution was not permitted. It is expected that the move to an open-source license will be beneficial for the SIESTA project and its large user community. On the other hand, the program will be able to incorporate functionally already existing in other GPL codes. On the other, the barrier for contributors will be lowered, as new developments will be more easily re-distributed.


Development and distribution of the program is now centralized at the Launchpad platform:


Users can download tarballs of released versions, as well as clone the source branches of the appropriate series directly. Prospective contributors are encouraged to become familiar with the Launchpad workflow and to read the specific documentation that is being prepared for SIESTA development.


The current stable series is '4.0' and the '4.0.1' will be released very soon. Users are encouraged to download it and use it for production runs.



This version includes:

  • Van der Waals functionals,
  • The new load-balancing code for real-space grid operations
  • A Wannier90 interface 
  • New-Orbita-Minimization-Method solver
  • Other improvements and bug fixes

RELEASE NOTES FOR SIESTA 4.0.1 (expected July 2017)

This version fixes and extends numerous things from the 4.0 release:

  • Better standard compliance in code structure,
  • Fix bug related to SlabDipoleCorrection which could not be turned off (lp:1630827)
  • Fix non-collinear bandstructure calculations (lp:1636100) 
  • Fix for 'nodes' basis generation option (lp:1625725)
  • Fixes VCA mixing of pseudos (lp:1633039)
  • Fixes integer energy specifications in Projected Density of States block (lp:1657584)
  • Added print-outs when GridCellSampling is used
  • TBtrans_rep changed the written DOS units to 1/eV (they were in 1/Ry)
  • Fix for Bader charge analysis (lp:1656273)
  • Fix memory problem when memory usage close to limit (lp:1665294)
  • Forced Diag.ParallelOverK to false if non-collinear spin configuration (lp:1666428)
  • Updated Eig2DOS to be more the same as gnubands (options are the same)
  • Forced Diag.ParallelOverK to false if non-collinear spin configuration (lp:1666428)
  • Updated Eig2DOS to be more the same as gnubands (options are the same)
  • Added Geometry.Must.Converge flag to ensure the relaxation has converged
  • Enabled internal walltime check to forcefully stop SIESTA after X seconds
  • Updated and fixes for ol-STM
    • Fix wrong fftw call
    • Enabled reading WFSX files
    • Added si001 test
  • Added new interpolation routine (originally from D.R.Hamann) for polynomial interpolation

To see other changes introduced to the 4.0 release series please refer to this page:






SIMUNE offers useful services to warrantee the efficient use of the code for any SIESTA user (industrial, academic or research), assist the community of users with a broader range of possibilities for the materials design (obtain new properties linking SIESTA to other codes, developing new interfaces, etc.) or to deal with the daily matters that require valuable time to solve. We also train researchers in the use of the code, help them facing their first materials design challenges, using the code efficiently or shorteninng the learning curve of the code.




An example of our tutorials: Basic SIESTA execution: energy optimization of H2 molecule




1.- The SIESTA Package: Code Compilation

2.- SIESTA execution

3.- Basic Exercise: Energy optimization of a H2 molecule

4.- Atomic orbital of finite range as a basis-set: basis-set convergence

5.- Optimization of material properties: Equilibrium Bulk Structure

6.- Optimization of material properties: Band Structure

7.- Optimization of material properties: Density of States (DOS)

8.- Optimization of material properties: Charge Density

9.- Molecular Dynamics in SIESTA

10.- LDA+U approximation in SIESTA



1.- TranSIESTA Compilation and Execution

2.- Transmission Curve: Hydrogen Chain 


Please,  ask us for a free the tutorial of your interest on (one tutorial maximum per request). There are more under development, please ask us if you do not find the one you need.


You can find other useful information about the SIESTA method and code in the SIESTA documentation section.


Prof. Junquera has also interesting tutorials for SIESTA in the following link:

It includes an interesting set of self-explained SIESTA exercises and a case study for SrTiO3 as system prototype to calculate:

-Lattice constant, bulk modulus and equilibrium energy

-Band structures

-Projected density of states

-Born effective charge

-Maximally localized Wannier functions





SIMUNE assists leading industrial, academic and research customers with the expert use of the popular and efficient SIESTA code, a standard in atomistic simulations. Apart from the design service, we offer support, training and development/integration of customized modules and/or interfaces for SIESTA.

SIMUNE makes it easy to start using SIESTA and/or TranSIESTA through customized and confidential assistance. We adjust our support to meet the users requirements and provide solutions to their specific problems.

Please, contact us>>  if you are interested in our services.