[Chemistry] My Chemical Romance

[Brogis1]

Abstract

Calculate entanglement entropies of orbitals and represent their mutual information matrix as in the Figure above (numbers correspond to the orbitals, the boldness of the lines connecting them is proportional to the magnitude of entanglement).

Description

Most likely locations of electrons around nuclei are represented by molecular orbitals. In chemistry, the number of molecular orbitals is usually very large and prohibits simulations of systems of research interest. Methods that select only a few relevant ones have been developed. A clever selection allows to describe the physics correctly and to reduce the computational cost significantly (i.e. reducing the number of qubits required for a simulation on a quantum quantum). Recently, a method based on the measurement of entanglement was implemented on classical computers. For example, the entanglement entropy can represent the amount of correlation between pairs of orbitals. Evaluation of this quantity brings insights into which orbitals are the most important (as a diatomic molecule gets stretched in Figure above) and which can be potentially neglected. The proposition is to evaluate on a quantum computer the entanglement entropies to construct the mutual information matrix I.

What you get:

• You will learn how to simulate molecules using Qiskit.
• I have partially working implementation of this project that needs to be adapted and tested.

This idea is based on:

• Paper: Orbital Entanglement in Bond-Formation Processes https://pubs.acs.org/doi/10.1021/ct400247p
• Abstract: " The accurate calculation of the (differential) correlation energy is central to the quantum chemical description of bond-formation and bond-dissociation processes. In order to estimate the quality of single- and multireference approaches for this purpose, various diagnostic tools have been developed. In this work, we elaborate on our previous observation [J. Phys. Chem. Lett.2012, 3, 3129] that one- and two-orbital-based entanglement measures provide quantitative means for the assessment and classification of electron correlation effects among molecular orbitals. The dissociation behavior of some prototypical diatomic molecules features all types of correlation effects relevant for chemical bonding. We demonstrate that our entanglement analysis is convenient to dissect these electron correlation effects and to provide a conceptual understanding of bond-forming and bond-breaking processes from the point of view of quantum information theory. "

Members

• @Supanut-Thanasilp, @HermanniH, @yamamoto-takahiro, @DPhyOmega
• Slack: @slackhandle email: example@example.com
• Qiskit Coach: @Brogis1 @atilag

Deliverable

Qiskit Aqua Module

GitHub repo

https://github.com/Brogis1/qiskit-aqua

[HermanniH]

I am potentially interested in working on this

[Brogis1]

Great, talk to me anytime if you want to talk more about it :)

[HermanniH]

Hey where are you?

[DPhyOmega]

I am also interested in this project but I'm not sure how much I can contribute. Where can I find you guys to discuss a bit more?

[yamamoto-takahiro]

I'm really into this project and would like to know more about this subject. Could you share a copy of this ref paper?

Thank you.

[Brogis1]

Great. I am now in Theatro, only guy with a qiskit baseball cap and all in black. Sitting on the left side, at the last table no 21. Talk anytime guys.

[Brogis1]

The paper can also be found on arxiv: https://arxiv.org/abs/1303.7207

[Supanut-Thanasilp]

I am interested in this project as well

[yamamoto-takahiro]

I'm in, Takahiro Yamamoto, Physicist.

[Brogis1]

Come to the table 20 at the front ! I will present the stuff to everybody to make it clearer.

[paulpaul60229]

hi i am CHO, CHIEN-HUNG.i am interesting in it as well

[Brogis1]

GitHub Repo: https://github.com/Brogis1/qiskit-aqua the code can be found in the qiksit-aqua/qiskit/chemistry It consists of 3 python files: orbital_mutual_information.py plot_mutual_information.py and run_orbital_mutual_information.py To run the code just execute: run_orbital_mutual_information.py It will run a VQE to find the ground state. From the ground state evalutate the mutual information matrix and plots the graph where the links between nodes represent the entanglement strength between spatial molecular orbitals and the size of the dot the orbital entropy.