RUQT

**RUQT** (Rowan University Quantum Transport) is a Fortran code for performing Landauer NEGF calculations using advanced electronic structure methods, particularly parametric 2-RDM (NEGF-RDM) and multi-configuration pair density function…

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Overview

**RUQT** (Rowan University Quantum Transport) is a Fortran code for performing Landauer NEGF calculations using advanced electronic structure methods, particularly parametric 2-RDM (NEGF-RDM) and multi-configuration pair density functional theory (NEGF-MCPDFT) for quantum transport through molecular junctions.

Reference Papers

Reference papers are not yet linked for this code.

Full Documentation

Official Resources

  • Source Repository: https://github.com/HoyLab-Rowan/RUQT
  • Documentation: Included in repository
  • License: Open source

Overview

RUQT (Rowan University Quantum Transport) is a Fortran code for performing Landauer NEGF calculations using advanced electronic structure methods, particularly parametric 2-RDM (NEGF-RDM) and multi-configuration pair density functional theory (NEGF-MCPDFT) for quantum transport through molecular junctions.

Scientific domain: NEGF quantum transport, 2-RDM, MCPDFT for molecular junctions
Target user community: Researchers studying quantum transport with advanced electronic structure methods beyond DFT

Theoretical Methods

  • Non-Equilibrium Green's Function (NEGF)
  • Landauer formalism
  • Parametric 2-RDM method (NEGF-RDM)
  • Multi-configuration pair DFT (NEGF-MCPDFT)
  • Molecular junction transport
  • Beyond-DFT transport

Capabilities (CRITICAL)

  • NEGF quantum transport
  • Landauer conductance
  • 2-RDM transport (NEGF-RDM)
  • MCPDFT transport (NEGF-MCPDFT)
  • Molecular junction simulation
  • Beyond-DFT accuracy

Sources: GitHub repository

Key Strengths

Beyond-DFT:

  • 2-RDM method for transport
  • MCPDFT for transport
  • Correlation effects in transport
  • Higher accuracy than DFT-NEGF

Advanced Methods:

  • NEGF-RDM framework
  • NEGF-MCPDFT framework
  • Multi-reference transport
  • Strong correlation support

Molecular Junctions:

  • Molecular transport
  • Junction I-V curves
  • Transmission functions
  • Contact effects

Inputs & Outputs

  • Input formats:

    • Molecular geometry
    • Electronic structure parameters
    • Junction configuration
  • Output data types:

    • Transmission functions
    • I-V curves
    • Conductance
    • Current-voltage characteristics

Interfaces & Ecosystem

  • Fortran: Core computation
  • Python: Wrapper scripts
  • Psi4/PySCF: Electronic structure

Performance Characteristics

  • Speed: Moderate (2-RDM/MCPDFT)
  • Accuracy: Beyond DFT
  • System size: Small molecules
  • Memory: Moderate

Computational Cost

  • Transport: Minutes to hours
  • Electronic structure: Minutes (separate)
  • Typical: Moderate

Limitations & Known Constraints

  • Small molecules: 2-RDM scaling limits size
  • Fortran compilation: Required
  • Limited documentation: Research code
  • Niche methods: 2-RDM/MCPDFT community

Comparison with Other Codes

  • vs Gollum: RUQT has beyond-DFT methods, Gollum is DFT/TB-based
  • vs Transiesta: RUQT uses 2-RDM/MCPDFT, Transiesta uses DFT
  • vs GreenCheetah: RUQT is advanced electronic structure, GreenCheetah is recursive GF
  • Unique strength: NEGF quantum transport with 2-RDM and MCPDFT beyond-DFT methods

Application Areas

Molecular Electronics:

  • Molecular junction transport
  • Single-molecule conductance
  • I-V characteristics
  • Contact effects

Strongly Correlated Transport:

  • Correlation effects in transport
  • Multi-reference transport
  • Transition metal complexes
  • Open-shell systems

Method Development:

  • Beyond-DFT transport benchmarking
  • 2-RDM transport validation
  • MCPDFT transport testing
  • Correlation-transport coupling

Best Practices

Electronic Structure:

  • Use appropriate active space
  • Check 2-RDM convergence
  • Validate MCPDFT against experiment
  • Compare with DFT-NEGF

Transport:

  • Use sufficient energy grid
  • Check transmission convergence
  • Validate I-V against experiment
  • Consider contact effects

Community and Support

  • Open source on GitHub
  • Developed at Rowan University (HoyLab)
  • Research code
  • Limited documentation

Verification & Sources

Primary sources:

  1. GitHub: https://github.com/HoyLab-Rowan/RUQT

Confidence: VERIFIED

Verification status: ✅ VERIFIED

  • Source code: ACCESSIBLE (GitHub)
  • Documentation: Included in repository
  • Specialized strength: NEGF quantum transport with 2-RDM and MCPDFT beyond-DFT methods

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