Tangelo v0.4.3 is here

Howdy, Tangelo users !

It's been a few months since the last release and things have been a little quiet on the repository: this was only temporary !

A bit before Christmas last year, Good Chemistry Company was acquired by SandboxAQ, and we're excited to take this project and its community to the next level as part of SandboxAQ. Since the beginning of the year, we already got to participate in QHack, the NYUAD hackathon, the BIG quantum hackathon, the UnitaryHACK, and we’ll be at QCE24 (IEEE quantum week) in September for our tutorial "Exploring Chemistry Workflows for Current and Future Quantum Computers with Tangelo".

SandboxAQ will make a more complete official announcement about Tangelo in the near future, and move the project to SandboxAQ's Github. This should not change anything for our users in practice: we'll try to make sure there are no broken hyperlinks in our documentation and tutorials ;)

We're seeing a lot of interest in Tangelo for applications in materials design and drug discovery: as always, we welcome your feedback, questions, bug reports, feature suggestions, and contributions of any kind to the project. Don't be shy ! This is your chance to steer the developments in a direction that better supports your interests and propels your research.

🎉 A Tangelo user recently got his first publication as first author in a journal: Simulating Vibronic Spectra by Direct Application of Doktorov Formulas on a Superconducting Quantum Simulator. What will you do with Tangelo ? 🍊

Credits

This release was possible thanks to the contributions of @cburdine, @king-p3nguin, @golanor, @anushkrishnav, @alexfleury-sb and @ValentinS4t1qbit, as well as the feedback of researchers from various institutions that suggested features and fixes !

Highlights of this release

New features

• DMET users can now specify a callable (function) to define an active space for fragments. See short example here.
• DMET now works with Hartree-Fock and MP2 solvers. We do not support the UHF mean field yet, but it should be available soon.
• The Rotoselect optimizer is now available and Rotosolver now requires 1 less energy evaluation, thanks to @cburdine.
• Multi-controlled rotations and phase gates (CRX, CRY, CRZ and CPHASE) are now supported when converting a circuit to Qiskit format with tangelo.linq.translate_circuit (@golanor).
• A quantum circuit can now be provided as a reference state in order to create a variational ansatz and the new method Circuit.fix_variational_parameters can cleanly make all gates in a circuit non-variational (@cburdine)

Fixes and updates

• Tangelo was modified to support Qiskit v1.0 and more recent versions of qiskit-ibm-runtime for hardware experiments.
• Tangelo has added support for PySCF v2.5.0+, thanks to @anushkrishnav
• The Circuit.draw method can now properly print variational gates whose parameters are strings (@anushkrishnav)

Tutorials and examples

• A new example notebook was contributed by @alexfleury-sb , intended to accompany his publication on ArXiv: “Non-unitary Coupled Cluster on Gate-based Quantum Computers”.

Deprecated

• The semi-empirical solver MINDO3 from PySCF is no longer supported and was removed from the dependencies.

Misc

• Python 3.8 is no longer supported in our automated tests and was replaced by Python 3.12. We let you refer to the respective installation requirements for dependencies (Psi4, etc) if necessary.
• Our Sphinx documentation is now part of our automated workflow and deployed on Github-pages ! It will thus always be in sync with the main branch from now on. Thanks a lot, @king-p3nguin !