DMFTpack

Official Resources

• Homepage: https://dmftpack.github.io/
• Source Repository: https://github.com/dmftpack/dmftpack
• License: LGPL-3.0

Overview

DMFTpack is a software package designed for performing DFT+DMFT (Density Functional Theory + Dynamical Mean-Field Theory) calculations. It provides a bridge between first-principles calculations and many-body techniques. A key feature is its inclusion of native impurity solvers such as Iterative Perturbation Theory (IPT) and Self-Consistent Second-Order Perturbation Theory (SC2PT), as well as interfaces to external solvers.

Scientific domain: Strongly correlated electron systems, Materials science, Electronic structure Target user community: Researchers in condensed matter physics studying correlated materials

Theoretical Methods

• Dynamical Mean-Field Theory (DMFT)
• Density Functional Theory (DFT) integration
• Iterative Perturbation Theory (IPT)
• Self-Consistent Second-Order Perturbation Theory (SC2PT)
• Continuous-Time Quantum Monte Carlo (CT-QMC) interface

Capabilities

• DFT+DMFT self-consistent loop
• Native impurity solvers (IPT, SC2PT)
• Support for external solvers (e.g., CT-QMC)
• Interface with OpenMX for DFT input
• Calculation of spectral functions
• Handling of local interactions

Key Strengths

Integrated Solvers:

• Comes with built-in IPT and SC2PT solvers, reducing the need for external dependencies for perturbative approaches.

OpenMX Interface:

• Specifically designed to interface with the OpenMX DFT code, facilitating efficient workflows.

Accessibility:

• targeted at making DMFT calculations more accessible with standard perturbative methods.

Inputs & Outputs

• Input formats:
  • OpenMX output files
  • Parameter files for DMFT loop and solver settings
• Output data types:
  • Self-energies
  • Green's functions
  • Spectral functions
  • Occupations

Interfaces & Ecosystem

• DFT Codes:
  • OpenMX
• External Solvers:
  • CT-QMC (via interface)

Advanced Features

• Projectors: Implements projection methods for mapping DFT Bloch states to local orbitals.
• Perturbative Approaches: Efficient solvers for regimes where perturbation theory is valid.

Performance Characteristics

• Efficiency: IPT and SC2PT are computationally much cheaper than QMC methods, allowing for faster calculations on applicable systems.
• Scalability: Depends on the underlying impurity solver and the specific system size.

Computational Cost

• Low: For IPT/SC2PT solvers.
• High: If using external CT-QMC solvers for complex impurities.

Limitations & Known Constraints

• Perturbative Solvers: IPT and SC2PT are limited to specific parameter regimes (e.g., weak to intermediate coupling) and may fail in strong coupling or specifically for certain multi-orbital problems compared to exact methods like QMC.
• Documentation: May be less extensive than major community codes like TRIQS.

Comparison with Other Codes

• vs TRIQS: DMFTpack is a more specific package, whereas TRIQS is a general library for building solvers.
• vs DFT+DMFT in VASP/QE: Standalone package focusing on the OpenMX ecosystem initially.

Verification & Sources

Primary sources:

1. Homepage: https://dmftpack.github.io/
2. GitHub: https://github.com/dmftpack/dmftpack

Verification status: ✅ VERIFIED

• Official homepage: ACCESSIBLE
• Source code: OPEN