Welcome to the 1QBit OpenQEMIST documentation!

Contents:

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

Ab initio simulation starts from first-principle quantum mechanical theory, describing the electronic structure of a molecule without making any empirical assumptions. The accurate prediction of the electronic structure of a molecule is key to the design of new materials, such as drug compounds and catalyst molecules, by helping to anticipate a material’s properties before its synthesis in the lab. However, obtaining this information using classical computers is computationally intensive, and the resources required for an exact solution scale exponentially with the size of the problem. Attempts to provide approximate approaches to this problem on classical computers have been to date either limited to small-sized systems or compromising on the accuracy of the simulation.

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. QEMIST is developed primarily in Python, and its API facilitates the use of quantum development environments at a lower-level.

1QBit has released 1QBit has released OpenQEMIST, offering the open source community an entry point to quantum computing and quantum chemistry simulation. It provides access to a portion of the functionalities of QEMIST, as open source software under an Apache 2.0 license, for the benefit of the rapidly growing community of quantum computing researchers and developers.

Both QEMIST and OpenQEMIST are by design agnostic with respect to quantum development platforms, in alignment with 1QBit’s unique hardware-agnostic approach. This enables users, developers, and industry experts to harness the power of the most-advanced computing resources and algorithms, without the need to learn the intricacies of each individual hardware platform or to maintain a complex infrastructure.

In addition to hybrid quantum–classical computing frameworks, OpenQEMIST is equipped with classical electronic structure solvers, such as the coupled-cluster and configuration interaction methods. Any of these classical solvers can be easily utilized as a highly accurate solver in PD techniques, such as the density matrix embedding theory (DMET) framework implemented in QEMIST.

In addition to hybrid quantum–classical computing frameworks, OpenQEMIST is equipped with classical electronic structure solvers, such as the coupled-cluster and configuration interaction methods. Any of these classical solvers can be easily utilized as a highly accurate solver in PD techniques, such as the density matrix embedding theory (DMET) framework implemented in QEMIST.

With a growing community of quantum computing researchers and industry partners, 1QBit aims to pave the road toward practical quantum-enabled simulation to further accelerate innovation in materials science and drug discovery.

Unlock the full potential of QEMIST for your particular problem, contact us.

Highlights of the First Version of OpenQEMIST

Further details are available in the OpenQEMIST reference manual. Source code and installation instructions are available on GitHub.

1. Density matrix embedding theory (DMET) based VQE: 1QBit has been exploring PD techniques, which have the potential to scale up the size of molecules that can be simulated by reducing the required quantum resources while maintaining the accuracy of the electronic structure calculation. DMET, a promising PD technique, divides a molecule into fragments and determines the electronic structure of each subsystem using a highly accurate calculation method. Examples of the DMET and DMET-VQE workflows are available in the “DMET Example” section of this documentation. The DMET module of OpenQEMIST is available on GitHub along with an interactive Jupyter notebook.

2. Variational Quantum Eigensolver (VQE) simulations: VQE is a hybrid quantum–classical algorithm for performing quantum chemistry simulations that requires a shallower circuit than conventional algorithms. An example of the VQE workflow is available in the “VQE Example” section of this documentation. The VQE module of OpenQEMIST is available on GitHub along with an interactive Jupyter notebook.

3. Integration of the Microsoft QDK: The above VQE sample demonstrates the integration of Microsoft Quantum Development Kit (QDK) with QEMIST. For more information on 1QBit’s collaboration with Microsoft and the release of OpenQEMIST, please see the Microsoft blog.

4. Integration with PySCF: OpenQEMIST is equipped with an interface to PySCF a Python-based electronic structure calculation package. OpenQEMIST utilizes PySCF to generate the second quantized molecular Hamiltonian for quantum-enabled simulations. The interface to PySCF allows users to access different classical solvers in QEMIST.

Contributing to OpenQEMIST

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

Citing OpenQEMIST

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.

Indices and tables