Official Resources
- Homepage: https://gitlab.com/marcodalessandro76/Fiesta
- Documentation: https://gitlab.com/marcodalessandro76/Fiesta/-/wikis/home
- Source Repository: https://gitlab.com/marcodalessandro76/Fiesta
- License: GNU GPL v3
Overview
Fiesta is an open-source code for calculating electronic excitations using many-body perturbation theory (GW approximation and Bethe-Salpeter equation) starting from plane-wave DFT calculations. Developed by Marco D'Alessandro and collaborators, Fiesta focuses on efficient GW/BSE implementations with emphasis on optical properties, core-level spectroscopy, and exciton physics. It interfaces with major DFT codes (Quantum ESPRESSO, VASP) and provides comprehensive tools for excited-state calculations.
Scientific domain: GW approximation, BSE, optical properties, MBPT
Target user community: Spectroscopy researchers, excited-state physicists, DFT users
Theoretical Methods
- GW approximation (G₀W₀, evGW)
- Bethe-Salpeter Equation (BSE)
- Random Phase Approximation (RPA)
- Plane-wave basis
- Pseudopotentials
- Core-level excitations
- Exciton physics
- Optical properties
Capabilities (CRITICAL)
- GW quasiparticle energies
- Accurate band gaps
- BSE optical spectra
- Exciton binding energies
- Core-level spectroscopy
- X-ray absorption (XAS)
- Optical absorption
- Interfaces with QE/VASP
- Open-source implementation
- Efficient algorithms
- Production calculations
Sources: Fiesta GitLab repository
Key Strengths
DFT Code Interfaces:
- Quantum ESPRESSO interface
- VASP interface
- Standard DFT output
- Flexible input
- Wide compatibility
Core-Level Spectroscopy:
- XAS calculations
- Core excitations
- Element-specific
- Experimental comparison
- Comprehensive treatment
Optical Properties:
- BSE implementation
- Exciton calculations
- Absorption spectra
- Oscillator strengths
- Accurate predictions
Open Source:
- GNU GPL v3
- Free software
- Transparent code
- Community development
- Educational value
Efficiency:
- Optimized algorithms
- Parallel implementation
- Production performance
- Reasonable cost
- Research quality
Inputs & Outputs
-
Input formats:
- QE wavefunctions
- VASP output
- Fiesta input files
- DFT ground state
-
Output data types:
- Quasiparticle energies
- Optical spectra
- XAS spectra
- Exciton eigenstates
- Band gaps
Interfaces & Ecosystem
-
Quantum ESPRESSO:
- Primary interface
- QE wavefunction input
- Tested workflow
- Standard integration
-
VASP:
- VASP interface
- Alternative DFT input
- Compatibility
-
Visualization:
- Spectral plotting
- Analysis tools
- Standard formats
Workflow and Usage
Typical Workflow:
- Run DFT calculation (QE or VASP)
- Prepare Fiesta input
- Run GW calculation
- Analyze quasiparticle energies
- Run BSE for optical properties
- Extract and visualize spectra
GW Calculation:
fiesta -i gw_input
# Computes GW corrections
BSE for Optics:
fiesta -i bse_input
# Solves BSE for excitons
Advanced Features
GW Implementation:
- G₀W₀ calculations
- evGW (eigenvalue SC)
- Efficient algorithms
- Plasmon-pole models
- Production quality
BSE Capabilities:
- Electron-hole interaction
- Exciton eigenstates
- Binding energies
- Optical absorption
- Singlet excitations
Core-Level Excitations:
- XAS implementation
- Core-hole treatment
- Element-specific spectra
- Edge calculations
- Experimental comparison
Parallelization:
- MPI parallelization
- Efficient scaling
- Production performance
- Large systems feasible
Performance Characteristics
- Speed: Good (optimized algorithms)
- Accuracy: Excellent for optical/XAS
- System size: Moderate to large
- Scaling: Parallel implementation
- Typical: Research calculations
Computational Cost
- GW: Standard GW cost
- BSE: Moderate additional expense
- Parallelization: Good scaling
- Production: Feasible
- Efficiency: Competitive
Limitations & Known Constraints
- DFT dependency: Requires QE or VASP
- Learning curve: MBPT expertise needed
- Documentation: Community-level
- Support: Developer and community
- Platform: Linux systems
Comparison with Other Codes
- vs BerkeleyGW: Fiesta more specialized features
- vs Yambo: Both comprehensive GW/BSE
- vs WEST: Fiesta includes XAS
- Unique strength: Open-source, XAS capabilities, QE/VASP interfaces, core-level spectroscopy
Application Areas
Optical Spectroscopy:
- Absorption spectra
- Exciton physics
- Optical properties
- Experimental comparison
- Materials characterization
X-ray Spectroscopy:
- XAS calculations
- Core-level excitations
- Element-specific
- NEXAFS
- Synchrotron experiments
Band Gaps:
- Accurate fundamental gaps
- Quasiparticle corrections
- Semiconductor properties
- Band structure refinement
Materials Science:
- Electronic excitations
- Optical properties
- Spectroscopy interpretation
- Materials design
Best Practices
DFT Preparation:
- Converged QE/VASP calculation
- Sufficient k-points
- Empty states included
- Quality ground state
GW Convergence:
- k-point convergence
- Cutoff parameters
- Empty bands
- Frequency grid
BSE Calculations:
- Appropriate transitions
- k-point sampling
- Exciton convergence
- Numerical parameters
XAS Calculations:
- Core-hole treatment
- Broadening parameters
- Edge selection
- Experimental comparison
Community and Support
- Open-source (GPL v3)
- GitLab repository
- Wiki documentation
- Developer support
- User community
- Active development
Educational Resources
- GitLab wiki
- Example calculations
- Tutorial files
- Published papers
- User contributions
Development
- Marco D'Alessandro (lead developer)
- Open development on GitLab
- Community contributions
- Regular updates
- Research-driven
Research Applications
- Optical properties
- X-ray spectroscopy
- Exciton physics
- Band gap predictions
- Spectroscopy theory
Technical Innovation
Core-Level Focus:
- XAS implementation
- Core excitations
- Element-specific
- Comprehensive treatment
Multiple DFT Backends:
- QE interface
- VASP interface
- Flexible framework
- Wide applicability
Open-Source MBPT
- Free GW/BSE code
- Transparent algorithms
- Community-driven
- Educational value
- Research accessible
Verification & Sources
Primary sources:
- GitLab: https://gitlab.com/marcodalessandro76/Fiesta
- Wiki documentation
- M. D'Alessandro et al., publications
- User manual
Secondary sources:
- GW/BSE literature
- XAS spectroscopy papers
- Application studies
- Method development
Confidence: VERIFIED - Active open-source code
Verification status: ✅ VERIFIED
- GitLab: ACCESSIBLE
- Documentation: Wiki available
- Source code: Open (GPL v3)
- Community support: Active
- Development: Regular commits
- Specialized strength: Open-source GW/BSE, core-level XAS spectroscopy, QE/VASP interfaces, optical properties, exciton calculations, production quality