Libra

This is the main page of the computational chemistry methodology discovery library, Libra

About

• extensive tutorials, example, and documentation. This resource is actively developed, but the older tutorials may not fully reflect the current stage of the code itself, so the tutorials demonstrating the older features may be failing - please let us know if you need to use any of those and run into problems.

• Read-the-Docs documentation This is far from being complete. The work in progress...

• old program website Not maintained for long time, but may still contain some useful info on some topics

Community and Support

• Click below to join our community: 👉 Join Slack

• Open an Issue - to ask questions or report a problem

• The following public forum exists, but hasn't been used for a while - use the Slack workspace instead

Installation

Please see here

Developers and Contributors

• Dr. Alexey Akimov (University at Buffalo, link )
  The main developer and maintainer of the code

• Dr. Daeho Han (University at Buffalo) Implementation of the exact-factorization (XF) methods, quantum trajectories surface hopping (QTSH), validating and testing Ehrenfest dynamics and other internals, implementing some model Hamiltonians

• Mr. Brendan Smith (University at Buffalo) Entangled trajectories Hamiltonian, NA-MD with spin-orbit coupling, NBRA workflows, BL-LZ NA-MD tutorials and examples, Libra/DFTB+, Libra/QE, Libra/ErgoSCF, Libra/CP2K, and Libra/Gaussian interfaces

• Mr. Mohammad Shakiba (Shahid Bahonar University of Kerman, Iran) Cube file processing scripts, Libra/CP2K and Libra/Gaussian, Libra/Libint2 interfaces

• Mrs. Story Temen (University at Buffalo) Implementation and testing of the HEOM codes

• Dr. Wei Li (Hunan Agricultural University) NA-MD with spin-orbit coupling

• Dr. Kosuke Sato (Toyota Research Lab) State reordering scripts, Libra/GAMESS interface (Libra-X)

• Dr. Ekadashi Pradhan (York University) Libra/QE interface, delta-SCF NA-M (Libra-X)

• Dr. Amber Jain (Indian Institute of Technology Bombay, India) Implementation and testing of the HEOM codes

• Dr. Xiang Sun (NYU Shanghai, China) Implementation and testing of the FGR codes

• Dr. Sophya Garashchuk (University of South Carolina) QTAG theory development

• Dr. Matthew Dutra (University of South Carolina) Implementation and testing of the QTAG codes

References

This code is provided in the hope it will be useful.

If you use Libra in your research, please cite the following paper:

The "main" Libra papers

• More recent overview of Libra's capabilities Shakiba, M.; Smith, B.; Li, W.; Dutra, M.; Jain, A.; Sun, X.; Garashchuk, S.; Akimov, A.V.* "Libra: A modular software library for quantum nonadiabatic dynamics" Software Impacts 2022 14, 100445

• The initial implementation Akimov, A. V. "Libra: An open-Source 'methodology discovery' library for quantum and classical dynamics simulations" J. Comput. Chem. 2016 37, 1626-1649

If you use any of the Libra's methods or implementation, please cite as appropriate:

Papers that describe various developments in Libra

• FISH: Fully-integrated surface hopping Han, D.; Shakiba, M.; Akimov, A. V. "Fully-Integrated Surface Hopping as Quantum Decoherence Correction in Nonadiabatic Dynamics" J. Phys. Chem. Lett. 2025 16, 7168-7176

• Multiple-state QTSH Han, D.; Martens, C. C.; Akimov, A. V. "Generalization of Quantum-Trajectory Surface Hopping to Multiple Quantum States" J. Chem. Theory Comput. 2025 20, 5022-5042

• F-tracking of excited states Akimov, A. V. "State Tracking in Nonadiabatic Molecular Dynamics Using Only Forces and Energies" J. Phys. Chem. Lett. 2024 15, 11944-11953

• FSSH-3, modified FSSH-2, implmenentation of GFSH Akimov, A. V. "The Fewest Switches Surface Hopping as An Optimization Problem" Mol. Phys. 2024 e2376893

• Exact Factorization methods: SHXF, MQCXF, MFXF Han, D.; Akimov, A.V. "Nonadiabatic Dynamics with Exact Factorization: Implementation and Assessment." J. Chem. Theory Comput. 2024 20, 5022–5042

• ML Hamiltonian mapping approach Shakiba, M.; Akimov, A.V. "Machine-Learned Kohn–Sham Hamiltonian Mapping for Nonadiabatic Molecular Dynamics." J. Chem. Theory Comput. 2024 20, 2992–3007

• TC-NBRA Akimov, A.V. "Energy-Conserving and Thermally Corrected Neglect of Back-Reaction Approximation Method for Nonadiabatic Molecular Dynamics" J. Phys. Chem. Lett. 2023 14, 11673-11683

• QTAG Dutra, M.; Garshchuk, S.; Akimov, A. "The Quantum Trajectory-guided Adaptive Gaussian Methodology in the Libra Software Package" Int. J. Quntum Chem. 2023. 123, e27078

• (generalized) Local diabatization Shakiba, M.; Akimov, A.V. "Generalization of the Local Diabatization Approach for Propagating Electronic Degrees of Freedom in Nonadiabatic Dynamics" Theor. Chem. Acc. 2023 142, 68

• xTB from cp2k/Libra interface for NA-MD in large-scale systems, k-point formulation, spin-adaptation Shakiba, M.; Stippel, E.; Li, W.; Akimov, A. V. "Nonadiabatic Molecular Dynamics with Extended Density Functional Tight-Binding: Application to Nanocrystals and Periodic Solids" J. Chem. Theory Comput. 2022 18, 5157-5180

• many-body effects, NA-MD with TD-DFT states Smith, B.; Shakiba, M.; Akimov, A. V. "Nonadiabatic Dynamics in Si and CdSe Nanoclusters: Many-Body vs. Single-Particle Treatment of Excited States" J. Chem. Theory. Comput. 2021 17, 678-693

• HEOM implementation Temen, S.; Jain, A.; Akimov, A. V. "Hierarchical equations of motion in the Libra software package" Int. J. Quant. Chem. 2020 120, e26373

• Belyaev-Lebedev-Landau-Zener Surface Hopping within the Neglect of Back-Reaction Approximation Smith, B.; Akimov, A. V. "Hot Electron Cooling in Silicon Nanoclusters via Landau-Zener Non-Adiabatic Molecular Dynamics: Size Dependence and Role of Surface Termination" J. Phys. Chem. Lett. 2020 11, 1456-1465

• Phase correction, Ehrenfest dynamics details, basis transformations (see the SI) Akimov, A. V.; "A Simple Phase Correction Makes a Big Difference in Nonadiabatic Molecular Dynamics" J. Phys. Chem. Lett. 2018 9, 6096-6102

You may find the following papers useful examples

Papers that utilize Libra

• Formulation of a fragment-based NA-MD Akimov, A. V. "Nonadiabatic Molecular Dynamics with Tight-Binding Fragment Molecular Orbitals" J. Chem. Theory Comput. 2016 12, 5719-5736

• Quasi-stochastic Hamiltonian for longer NA-MD Akimov, A. V.; "Stochastic and Quasi-Stochastic Hamiltonians for Long-Time Nonadiabatic Molecular Dynamics" J. Phys. Chem. Lett. 2017 8, 5190-5195

• Entrangled-trajectories Hamiltonian dynamics to capture quantum effects of nuclei Smith, B. A.; Akimov, A. V. "Entangled trajectories Hamiltonian dynamics for treating quantum nuclear effects" J. Chem. Phys. 2018 148, 144106

• Inclusion of the Spin-orbit coupling in NA-MD Li, W.; Zhou, L.; Prezhdo, O. V.; Akimov, A. V. "Spin-Orbit Interactions Greatly Accelerate Nonradiative Dynamics in Lead Halide Perovskites" ACS Energy Lett. 2018 3, 2159-2166