A Python package for quantum chemistry and physics.

QuantNBody is a Python package that facilitates the implementation and manipulation of quantum many-body systems composed of fermions or bosons. It provides a quick and easy way to build many-body operators and wavefunctions, enabling access (in just a few lines of Python code) to quantities and objects of interest for theoretical research and method development. This tool can also be greatly helpful for pedagogical purposes and to illustrate numerical methods for fermionic or bosonic systems.

Introduction

• What is QuantNBody ?
• Brief illustration of what is possible
• How to contribute
• Support

How to install

• Installation and Running
  • Required packages
  • Installation of QuantNBody

Tutorials and examples

• A few remarks
• Tuto 1: first steps with the package
  • Philosophy of the package
  • Let us first import the package !
  • Building a many-body basis
  • Building and storing the \(a^\dagger_{p,\sigma} a_{q,\tau}\) operators
  • Building our first many-body Hamiltonian : a fermi-Hubbard molecule
• Tuto 2: playing with many-body wavefunctions
  • Building first the many-body basis and the \(a^\dagger_{p,\sigma} a_{q,\tau}\) operators
  • Building our own many-body wavefunction
  • Building filtered lists of many-body states
  • Applying excitations to a state
• Tuto 3: electronic structure Hamiltonian and spin operators
  • Electronic structure Hamiltonian
    • Plotting the resulting H\(_4\) PES
  • Building spin operators to check the spin symmetry of the states
• Tuto 4: the Bose-Hubbard system
  • Introduction : the Bose-Hubbard system
  • Importing the required libraries
  • Defining the basic properties of the system
  • Building the essential tools for the QuantNBody package
  • All-in-one function
  • Applying the function to get information from the system
  • Visualizing the resulting wavefunction in the many-body basis
  • Checking the implementation : comparing different ways to estimate the groundstate energy
• Tuto 5: Hybrid Fermion-Boson Systems
  • Step 1: Building a hybrid many-body basis
  • Step 2: About building operators in the hybrid many-body basis
  • Step 3: Build the fermionic \(\hat{a}^\dagger \hat{a}\) operator in the hybrid basis
  • Step 4: Build the bosonic \(\hat{b}\) and \(\hat{b}^\dagger\) operators in the hybrid basis
• Tuto 6: Hybrid fermion-boson Hamiltonians: Hubbard-Holstein and polaritonic chemistry
  • Example 1: Hubbard-Holstein model
    • Step 1: Building the Hamiltonian
    • Step 2: Computing time-independent observables
    • Step 3: Computing time-dependent observables
  • Example 2: Polaritonic chemistry
    • Step 1: Building the Hamiltonian
    • Step 2: Computing time-independent properties

List of implemented functions

• Note on the structure of the package
• Fermionic systems
  • Basic functions for the creation of many-fermion systems
  • Many-body Hamiltonians and excitations operators
  • Spin operators
  • Creating/manipulating/visualizing many-body wavefunctions
  • Reduced density matrices
  • Functions to manipulate fermionic integrals
  • Quantum embedding transformations (Householder)
  • Psi4 calculation helper
  • Orbital optimization
• Bosonic systems
  • Basic functions for the creation of many-boson systems
  • Many-body Hamiltonians and excitations operators
  • Creating/manipulating/visualizing many-body wavefunctions
  • Reduced density matrices
  • Functions to manipulate bosonic integrals
• Fermionic-Bosonic hybrid systems
  • Basic functions for the creation of many-fermion/boson hybrid systems
  • Many-body Hamiltonians and excitations operators
  • Spin operators
  • Creating/manipulating/visualizing many-body wavefunctions
  • Reduced density matrices
  • Functions to manipulate fermionic-bosonic hybrid integrals

How to cite

• How to cite

Indices and tables

• Index

• Search Page