Siesta

Siesta performs density-functional theory (DFT) electronic-structure calculations and ab initio molecular dynamics simulations of molecules and solids.

Key Features:

• Finite-support pseudo-atomic orbitals: Uses finite-support pseudo-atomic orbitals as localized basis sets for electronic-structure representation.
• Norm-conserving pseudopotentials: Employs norm-conserving pseudopotentials for core-electron treatment.
• Real-space grid: Represents charge density and potentials on a real-space grid and computes associated matrix elements on that grid.
• Spin-orbit interaction: Implements full spin-orbit interaction for relativistic effects.
• Ballistic electron transport: Supports non-repeated and multiple-contact ballistic electron transport calculations.
• DFT+U and hybrid functionals: Includes DFT+U and hybrid functionals for improved treatment of correlated systems.
• Time-dependent DFT: Provides time-dependent DFT capabilities for dynamic electronic processes.
• Reduced-scaling solvers: Implements novel reduced-scaling solvers to reduce computational cost.
• Density-functional perturbation theory (DFPT): Offers DFPT for computing material responses to perturbations.
• Van der Waals functionals: Includes efficient non-local density functionals to account for van der Waals interactions.
• Molecular dynamics: Provides ab initio molecular dynamics with enhanced MD options.
• Wannier90 interoperability: Interfaces with Wannier90 for electronic structure post-processing.
• AiiDA plugin: Provides an AiiDA plugin for workflow automation and integration.
• Lua scripting: Supports Lua scripting to steer calculations programmatically.
• Post-processing utilities: Includes various post-processing utilities for data analysis and visualization.
• Pseudopotential Markup and ES libraries: Contributes to the Pseudopotential Markup Language and integrates with the ELectronic Structure Infrastructure library of solvers.

Scientific Applications:

• Electronic-structure calculations: Compute ground-state electronic structure and band structures of molecules and solids.
• Materials response and phonons: Study material responses and phonons using density-functional perturbation theory.
• Nanoelectronic transport: Analyze ballistic electron transport in nanostructures and multi-contact devices.
• Time-dependent phenomena: Simulate dynamic electronic processes with time-dependent DFT.
• Strongly correlated materials: Model correlated systems using DFT+U and hybrid functionals.
• Dispersion-dominated systems: Simulate van der Waals and dispersion-bound systems using non-local vdW functionals.

Methodology:

Siesta uses finite-support pseudo-atomic orbitals, norm-conserving pseudopotentials, and a real-space grid to represent charge density and potentials and to compute matrix elements; it implements density-functional theory (including DFT+U and hybrid functionals), time-dependent DFT, density-functional perturbation theory, full spin-orbit interaction, reduced-scaling solvers, and supports ballistic electron transport calculations.