BoltzTraP

Official Resources

• Homepage: https://www.imc.tuwien.ac.at/forschungsbereiche_theorie_und_simulation/software_packages/boltztrap/
• Documentation: Included in source distribution
• Source Repository: https://www.imc.tuwien.ac.at/forschungsbereiche_theorie_und_simulation/software_packages/boltztrap/
• License: GNU General Public License v3.0

Overview

BoltzTraP (Boltzmann Transport Properties) is a code for calculating electronic transport properties (Seebeck coefficient, electrical conductivity, electronic thermal conductivity) as a function of temperature and chemical potential. It solves the semi-classical Boltzmann transport equation within the constant relaxation time approximation (RTA), using a smoothed Fourier interpolation of the bands.

Scientific domain: Electronic transport, thermoelectrics, Boltzmann transport equation
Target user community: Thermoelectric materials researchers, solid-state physicists

Theoretical Methods

• Semi-classical Boltzmann transport equation
• Constant relaxation time approximation (RTA)
• Rigid band approximation
• Smoothed Fourier interpolation of band energies
• Calculation of transport distribution function tensor

Capabilities (CRITICAL)

• Calculation of Seebeck coefficient (thermopower)
• Electrical conductivity (relative to relaxation time τ)
• Electronic thermal conductivity
• Power factor
• Hall coefficient
• Temperature and doping dependence of transport properties
• Interfaces with VASP, WIEN2k, Quantum ESPRESSO, CASTEP, etc.

Sources: BoltzTraP website, Comp. Phys. Comm. 175, 713 (2006)

Inputs & Outputs

• Input formats: intra (structure/energy window), energy (eigenvalues), struct (WIEN2k structure format)
• Output data types: .trace (transport vs μ/T), .condtens (tensors), .sig (conductivity spectral function)

Interfaces & Ecosystem

• WIEN2k: Native interface (x_trans BoltzTraP)
• VASP: Can be used via vasp2boltz.py scripts
• Quantum ESPRESSO: Interface available
• Boltztrap2: Modern Python successor (separate tool)

Workflow and Usage

1. Perform DFT calculation with dense k-mesh.
2. Prepare input files (case.intrans, case.energy).
3. Run BoltzTraP.
4. Analyze output files (case.trace).

Performance Characteristics

• Very fast (minutes) compared to DFT
• Fourier interpolation step scales with number of k-points and bands

Application Areas

• Thermoelectric materials screening
• Doping optimization
• Transport in metals and semiconductors
• Hall effect simulations

Community and Support

• Developed by Georg Madsen (TU Wien) and David Singh
• Widely cited legacy code
• Superseded by BoltzTraP2 for new projects

Verification & Sources

Primary sources:

1. Homepage: https://www.imc.tuwien.ac.at/forschungsbereiche_theorie_und_simulation/software_packages/boltztrap/
2. Publication: G. K. H. Madsen and D. J. Singh, Comp. Phys. Comm. 175, 713 (2006)

Confidence: VERIFIED

Verification status: VERIFIED

• Website: ACTIVE
• Documentation: AVAILABLE
• Source: OPEN (GPL)
• Development: STABLE (Legacy)
• Applications: Thermoelectrics, transport, RTA