PyQED

Getting started

  • Installation
  • Five-minute quickstart
  • Tutorials and learning paths
  • Examples Gallery
    • Quantum Chemistry
    • Multiconfigurational Methods
    • DVR and Grid Dynamics
    • Nonadiabatic Dynamics
    • Geometric Quantum Dynamics
    • Floquet and Light-Matter Models
    • Open Quantum Systems and Spectroscopy
    • Running Examples
    • Related Pages

Concepts and user guides

  • Theory Overview
  • User guides
  • Backends and Integral Representations
  • Quantum Chemistry
  • Hartree-Fock Analysis
  • MP2 and COMP2
  • GW and BSE
  • TDDFT and Ehrenfest Dynamics
  • Matrix Product States
  • Discrete Variable Representation
  • Geometric Quantum Dynamics
  • Floquet
  • Models
  • Nonadiabatic Molecular Dynamics
  • Polariton
  • HEOM and structured baths

API and implementation

  • API entry points
  • Quantum Chemistry Architecture
  • Non-Abelian DMRG Design Notes

Evidence and citation

  • Capability maturity
  • Benchmarks and validation
  • Citing PyQED

Develop and get help

  • Development and contribution
  • Support and problem reports
  • People and project organization
PyQED
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Examples Gallery

The repository includes runnable entry points under examples/. This page groups useful starting points by topic. Some are small smoke cases, while others are expensive research workflows with external dependencies and cached data. A listing here does not promote a workflow beyond the maturity shown in Capability maturity.

Run an example from the repository root and inspect its imports, parameters, and output paths before execution. For research use, preserve the exact script commit and a Benchmarks and validation manifest.

Quantum Chemistry

  • examples/qchem/sa_casscf_factor.py: native factorized, state-averaged CASSCF on a small H4 model.

  • examples/qchem/gw_qsgw.py: native H2 RHF followed by small GW-family workflows.

  • examples/qchem/casscf.py: native CASSCF workflow.

  • examples/qchem/casscf_factor_vs_dense.py: compare dense and factorized CASSCF paths.

  • examples/qchem/comp2_h2o.py: COMP2 example on water.

  • examples/qchem/gw_qsgw.py: G0W0, eigenvalue-self-consistent GW, and qsGW on H2.

  • examples/qchem/rttdhf_h2_kick_spectrum.py: real-time TDHF kick spectrum for H2.

  • examples/qchem/tddmrg_h2_threeway_compare.py: time-dependent DMRG comparison example.

Multiconfigurational Methods

  • examples/qchem/mcscf/secondorder_casscf.py: second-order CASSCF example.

  • examples/qchem/mcscf/cas_pyscf.py: CAS comparison workflow.

  • examples/qchem/mcscf/wfn_overlap.py: wavefunction overlap example.

  • examples/qchem/lif_casscf_scan.py: LiF CASSCF scan.

  • examples/qchem/casscf_compare_vs_pyscf.py: CASSCF comparison against PySCF.

DVR and Grid Dynamics

  • examples/dvr/sddvr.py: simultaneous-diagonalization DVR.

  • examples/dvr/gwp_sddvr_2d_independent_ho.py: Gaussian-wavepacket SD-DVR on a two-dimensional harmonic oscillator.

  • examples/dvr/shin_metiu.py: Shin-Metiu DVR model.

  • examples/qchem/gdvr_h2_rhf.py: grid-DVR RHF example for H2.

  • examples/qchem/gdvr_h4_rhf.py: grid-DVR RHF example for H4.

Nonadiabatic Dynamics

  • examples/namd/ehrenfest.py: Ehrenfest dynamics.

  • examples/namd/ehrenfest_histories.py: trajectory/history handling.

  • examples/namd/abinitio_ehrenfest_pyscf.py: ab initio Ehrenfest workflow using PySCF as a backend.

  • examples/namd/lif_population_dynamics.py: LiF population dynamics.

Geometric Quantum Dynamics

  • examples/ldr/ldr.py: locally diabatic representation dynamics.

  • examples/ldr/abinitio.py: ab initio LDR workflow.

  • examples/ldr/abinitio_pyscf.py: PySCF-backed ab initio LDR workflow.

  • examples/ldr/overlap_matrix_approximation_2D.py: approximate electronic overlap matrices on a two-dimensional grid.

  • examples/ldr/h3/1scan_PES_H3+.py: H3+ adiabatic potential scan.

  • examples/ldr/h3/2calculate_overlap_nearest_neighbor.py: nearest-neighbor electronic-state overlaps.

  • examples/qchem/bo_hamiltonian_derivatives.py: BO Hamiltonian derivative construction.

  • examples/qchem/bo_hamiltonian_derivatives_normal_modes.py: BO derivative projection onto normal modes.

Floquet and Light-Matter Models

  • examples/floquet/two_level_system.py: driven two-level model.

  • examples/floquet/RiceMele.py: Rice-Mele model.

  • examples/floquet/Floquet_topological_phase_diagram.py: Floquet phase diagram example.

  • examples/test_cavity.py: cavity-QED smoke example.

Open Quantum Systems and Spectroscopy

  • examples/heom.py: hierarchical equations of motion example.

  • examples/deom.py: dissipaton equation of motion example.

  • examples/redfield.py: Redfield dynamics example.

  • examples/signals/absorption.py: absorption signal example.

  • examples/2DES.py: two-dimensional electronic spectroscopy example.

  • examples/TPA.py: two-photon absorption example.

Running Examples

Run examples from the repository root so relative data files resolve correctly:

PYTHONPATH=. python examples/qchem/sa_casscf_factor.py
PYTHONPATH=. python examples/dvr/fedvr_harmonic_oscillator.py

Some examples require optional dependencies or compiled backends. If an example imports PySCF, PyVista, libxc, or plotting packages, install those dependencies separately before running it.

examples/qchem/h2.py is a PySCF-based potential-curve script despite its generic filename; it is not the native PyQED quickstart. Use Five-minute quickstart for the tested native entry path.

Related Pages

  • Hartree-Fock Analysis

  • MP2 and COMP2

  • GW and BSE

  • TDDFT and Ehrenfest Dynamics

  • Geometric Quantum Dynamics

  • CASCI and CASSCF

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