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Quantum chemistry simulation library.

Project description



Harnessing the combined power of emerging quantum computing technologies and state-of-the-art classical techniques, the Quantum-Enabled Molecular ab Initio Simulation Toolkit, or QEMIST, is 1QBit’s innovative solution to a fundamental and intractable problem in chemistry: ab initio simulation of molecules.

QEMIST is designed to enable the accurate calculation of molecular properties by leveraging advanced problem decomposition (PD) techniques and quantum computing. The variety of PD techniques implemented in QEMIST enables massively parallel simulations by breaking down a computational chemistry task into smaller, independent subproblems. These subproblems can use a combination of interfaces to various classical and quantum solvers to achieve a higher level of accuracy for large-scale, practical molecular simulations.

OpenQEMIST provides access to a portion of the functionalities of QEMIST as open source software under an Apache 2.0 license. For more information about the full functionality of QEMIST and to obtain additional information, please consult our main product page.

Getting started

To get started, install the package, then see the Jupyter notebooks for example usage.

To use the Rigetti integration, see the instructions here to install and configure the QVM and Quilc compiler. Alternatively, use the provided docker-compose file to set up the environment.

To use the Microsoft QDK integration follow the instructions here to install the required dependencies.

Architechture of OpenQEMIST

OpenQEMIST is organized into three layers: problem decomposition, electronic structure solvers, and hardware backends. The problem decomposition layer is responsible for splitting the input molecule into smaller subproblems and treating these using one particular eigenvalue solver (conceivably, fragments could be treated using multiple solvers), then processing these results into an overall output energy. Some electronic structure solvers use classical methods, while others use wrappers over quantum algorithms running on quantum computing emulators and simulators from quantum platform providers. The quantum solver backend layer implements a common interface over libraries, emulators, and simulators of quantum hardware.

As OpenQEMIST includes only a portion of the functionalities incorporated in QEMIST, DMET is the only problem decomposition technique open sourced in our initial release. This release includes the Full CI and coupled-cluster with single and double excitations (CCSD) electronic structure solvers, as well as a quantum electronic structure solver based on the Variational Quantum Eigensolver (VQE) algorithm.

On the hardware backend, this initial release is integrated with the Microsoft Quantum Development Kit for running the VQE algorithm.


We welcome contributions to OpenQEMIST! Please open an issue or submit a pull request on GitHub to start the process.


If you use OpenQEMIST in your research, please cite

Takeshi Yamazaki, Shunji Matsuura, Ali Narimani, Anushervon Saidmuradov, and Arman Zaribafiyan "Towards the Practical Application of Near-Term Quantum Computers in Quantum Chemistry Simulations: A Problem Decomposition Approach" Published on arXiv on Jun 4, 2018.

Copyright 1QBit 2019. This software is released under the Apache Software License version 2.0.

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