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Modeling realistic chemistry with quantum computing

How IBM, Cleveland Clinic, and RIKEN are exploring chemistry research with quantum-centric supercomputers

Bringing new drugs to market is really hard

New infectious diseases emerge annually, threatening millions of people around the world. Meanwhile, existing pathogens evolve resistance to treatment. Medical science can struggle to keep up.

Researchers turn to high-performance computers to identify promising chemical compounds for medicine by studying their interactions with the human body. However, the medical industry faces challenges as it works to develop new drugs and fight disease.


High cost

At present, the average cost to bring a new drug to market is ~$2 billion.


Long runways

New regulations, cost constraints, and expiring patents lead to fewer new drugs for the same amount of R+D effort.


Meeting success criteria

Preclinical studies may fail to reveal toxicity, wasting resources if flagged later in the development arc.


Computational load

Today’s chemistry simulations require vast computational resources to accurately simulate large molecules.

Accurately modeling chemical interactions is critical

Developing new drugs amid these challenges requires more efficient research and development methods.

When researching molecules, scientists need to isolate them and model their underlying composition. They also must anticipate how they will interact with other compounds in the human body.

Click on the tiles below to learn about different key molecular properties of interest for medicinal chemistry.

Supramolecular interactions

Supramolecular interactions are those between different molecules, such as interactions between molecules that make up the drug and a target protein found in pathogens or the human body.

Conformational energies

Biomacromolecules

Supramolecular interactions

Supramolecular interactions:

Supramolecular interactions are those between different molecules, such as interactions between molecules that make up the drug and a target protein found in pathogens or the human body.

Two molecules. One next to the other

Accelerating research in chemistry

Quantum computers

Quantum computers rely on a unique underlying hardware based on the principles of quantum mechanics. They can solve certain problems beyond the ability of classical computers alone.

Quantum + Classical

Quantum computers won’t solve every problem more efficiently than classical supercomputers, which are better at performing sequential logical tasks. So we are leveraging the power of both by creating quantum-centric supercomputers. Just like graphics processing units (GPUs) accelerate supercomputers today, QPUs (quantum processing units) could accelerate supercomputers tomorrow.

Applied exploration

Researchers and industry leaders worldwide are developing quantum-centric supercomputing techniques for challenging problems. For example, startup QunaSys (opens in a new tab) offers a function (opens in a new tab) to users of IBM Quantum Platform, that implements a quantum-centric technique for chemistry called quantum-selected configuration interaction, or QSCI.

A schematic drawing where a laptop communicates with a container where several quantum computers are drawn and this container in turn communicates by several lines with another container which includes what looks like several servers and other similar objects

Harnessing the power of quantum

Partnering with RIKEN, IBM explored one method for simulating chemistry with quantum-centric supercomputers called sample-based quantum diagonalization (opens in a new tab), or SQD. It uses quantum to generate measurements corresponding to electronic configurations, then uses classical to process those configurations into an answer robust to quantum computing noise. This technique has the potential to outperform what classical approximation methods could do alone.

Take an iron-sulfur cluster [4Fe-4S], for instance. On today’s pre-fault-tolerant quantum computers alone, it would take 3 million years to model. SQD offers a way to study this compound before the emergence of fault-tolerant quantum computing.

Groups of molecules joined between them
  • Pre-fault-tolerant quantum computing

    3M years

    A single quantum computer running a VQE algorithm

  • Fault-tolerant quantum computing

    13 days

    An error-corrected quantum computer running phase estimation

  • Quantum-centric supercomputing

    2 hrs

    IBM Heron processor + RIKEN’s Fugaku supercomputer running SQD

Taking it further with quantum

As you can see, we don't have to wait for fault-tolerant quantum systems to start exploring chemistry applications with quantum. Cleveland Clinic is extending the RIKEN work to run molecular simulations relevant for drug discovery. New work combines quantum and classical using SQD to obtain information on the energies of molecules in a way that is robust to the noise inherent to quantum computation.

Explore the demos below to see how quantum-centric supercomputing tackles two critical chemical research tasks: modeling supramolecular interactions and conformational energies. They compare SQD with state-of-the-art classical methods used to approximate these properties today.

In this demo, we show computations of weak interactions between a pair of water molecules connected via hydrogen bonding. The x-axis shows the distance between the oxygen atoms of two water molecules, and the y-axis shows the energy required to separate the molecules. The results show that quantum competes with classical to produce precise answers for this small-scale problem.

Explore methods

A classical computational chemistry method that approximates the energies of complex systems by focusing on all of the possible excitations from a set of predetermined orbitals

A quantum-centric supercomputing approach that first calculates the energy of a system on a quantum computer, and then produces a more accurate answer with an iterative classical correction.

Results:

Average distance between points

2.54e-08 kcal/mol

The small average difference between the energies from each method demonstrates excellent agreement between the quantum and classical methods for this example.

Outlook

These demos show that the output of quantum-centric supercomputing methods can already match the precision of leading classical methods for certain use cases.

Quantum-centric supercomputing can go beyond the limitations of either quantum or classical computing alone and has the potential to reduce computational load and the costs required for analyzing drug compounds and interactions. These advances will help accelerate the industry and usher in a new era of computing.

Get started

Want to explore the potential benefits of quantum for your industry?

Explore IBM Quantum Platform to get access to cloud-based quantum hardware, news, and world-class learning material. The Qiskit Functions catalog helps developers accelerate their workloads with a suite of abstracted services for key research applications.

Some screenshots of the ibm quantum platform