QuChem

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quchem is a python library for quantum chemistry VQE simulations.

The quchem module:

• Uses PySCF to obtain the molecular Hamiltonian of a system of interest
• Can use Psi4 to obtain the molecular Hamiltonian of a system of interest too

• The openfermion library converts this to a qubit Hamiltonian

  • Currently only the Jordan-Wigner and bravyi-kitaev transforms are used

• Google's cirq library is used to build quantum circuits

  • Hartree-Fock (HF) + Unitary Coupled Cluster Single Double (UCCSD) excitations are currently used as the Ansatz
  • Each quantum circuit is simulated using a wrapper for cirq's simulator.

To Install

quchem is a pure python package. The code is hosted on github and if the dependencies are satisfied, a development version can be installed directly by cloning the github repo and running:

git clone https://github.com/AlexisRalli/VQE-code.git

pip install -r requirements.txt
python setup.py develop

Special Dependencies

Note

To install Psi4 please follow Psi4_install for anaconda distribution do:

conda config --add channels http://conda.anaconda.org/psi4
#check
cat ~/.condarc
>> channels:
  - http://conda.anaconda.org/psi4
  - defaults

#to install
conda install psi4

Note

TensorFlow version 1 required for one optimizer (only requires installing if used)! To install for anaconda distribution do:

conda install -c conda-forge tensorflow=1.15

Documentation

The full documentation can be found at: http://quchem.readthedocs.io/en/latest/.