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Reasoning from
chemistry's first principles.

Chemstack combines molecular structure, reaction physics, and experimental feedback to make decisions about chemistry, not predictions about text.

Molecular propertiesReaction relationshipsScientific evidenceExperimental knowledgetarget moleculeScientific decision
Why chemistry is different

Chemistry cannot be solved by pattern matching alone.

General-purpose AI is trained to recognise patterns in language and generate plausible responses.

Chemistry requires something different: reasoning about molecular structure, transformations, and reaction conditions to determine what will actually work. Chemstack is built around this distinction.

General AI

Pattern recognition

Text
Patterns
Similar reactionPublished procedureLikely answer
Plausible answer

Learns relationships in language and existing information.

Chemstack AI

Scientific reasoning

Molecule

structure · electronic structure

Chemical transformations

mechanism · disconnections · reaction classes

Molecular interactions

kinetics · thermodynamics · quantum descriptors

Experimental evidence

observed outcomes · scale-up physics

Scientific decision

conditions · regio- & chemoselectivity

Reasons across chemical structure, reaction behaviour, scientific evidence, and experimental outcomes.

General AI can tell you what has been written about a reaction.

Chemstack is designed to reason about whether that chemistry makes sense for the molecule in front of you.

Chemistry World Model

A deeper representation of chemistry.

A reaction tells us what transformed. A procedure tells us how it was performed. Molecular interactions help explain why a substrate behaves the way it does. Chemstack brings these layers together into a scientific representation of applied chemistry.

Molecular Interactions
Layer 1
Chemical Transformations
Layer 2
Procedures & Conditions
Layer 3
Scientific Evidence
Layer 4
Chemistry World Model

One shared scientific context for every reasoning system in Chemstack.

These aren’t separate databases. They are connected representations of the same chemistry, each layer giving meaning to the one beneath it. Hover a layer to lift it out.

Scientific reasoning

From chemical understanding to scientific decisions.

Understanding chemistry is only the beginning. Different scientific questions require different kinds of reasoning. Chemstack uses specialized intelligence systems to explore possibilities, predict outcomes, and learn from experimental reality.

Question 01

What is scientifically possible?

Deep Research

Question 02

What is most promising?

Reaction Virtualisation

Question 03

Why did reality differ?

Optimization
01 · Deep Research
What are all the ways this molecule could be made?

Search the chemistry space, not just the literature.

Deep Research works the way a chemist does: backwards from the target, breaking it at the bonds most likely to come apart. It generates every viable disconnection, then ranks them on the chemistry that decides whether a route survives: reactivity, selectivity, and the features that make a step work or fail. An ensemble of retrosynthetic, functional-group-aware models does the generating; a chemistry-first ranking model does the scoring.

The goal isn’t the first plausible synthesis. It’s to construct and rank the full chemical search space, so the route you run is the best one, not the first one found.

Under the hood

Disconnection generationFunctional-group-aware modelsReaction featuresLearning-to-RankChemical embeddings
Retrosynthetic search space
TARGET MOLECULEmillions of possible disconnectionsCHEMISTRY-FIRST RANKING~100 feasible routesRoute 1rank 1Route 2Route 3TOP ROUTESGENERATERANK
02 · Reaction Virtualisation
Which conditions give us the best chance of success?

Visualise the experiment before running it.

Reaction Virtualisation takes the most promising pathways and explores the experimental space around them. It weighs yield, process constraints, cost, and known reactivity to generate candidate DOE conditions.

The Virtual Reactor then reasons about reaction behaviour using molecular structure and quantum descriptors to estimate how those conditions are likely to perform.

Under the hood

DOE generationReaction precedentChemistry constraintsCost modellingThermodynamic signalsKinetic signalsSite-specific reactivity
Experimental decision funnel

Top routes

Route 1Route 2Route 3

Evaluate

YieldPaper costPuritySafetyAvailability

DOE space · candidate conditions

Chemist constraintsMaximize yieldMinimize costMaximize purity

Top DOE candidates

DOE-07DOE-14DOE-27

Virtual Reactor

Simulated before the bench

Predicted outcome

91%

Predicted yield

94%

Predicted purity

+12°C

Temperature Δ

03 · Optimization
Why did the experiment behave differently from the prediction?

Turn experimental deviations into the next experiment.

Chemistry rarely behaves exactly as predicted. This analyses the gap between expected and observed outcomes, examining reaction conditions, substrate behaviour, and impurity patterns to identify the likely cause.

The result isn’t just an explanation. It’s the next experiment.

Under the hood

Prediction vs observationRoot-cause analysisReaction-condition analysisImpurity patternsIterative optimisation
Prediction vs reality
Predicted
91%
Observed
63%

Δ −28 pts · the gap is information

Optimization analysis

Reaction conditionsSubstrate behaviourImpurity profileExperimental evidence

Root cause

Catalyst inhibition: trace impurity in the substrate lot

Next experiment

Guard bed + substrate purification

Optimized condition

89% observed on the next run
One intelligence system

Discovery, prediction, and learning are connected.

Deep Research expands the possibilities. Reaction Virtualisation evaluates which possibilities are most promising. Optimization learns from what actually happened. Together, they create a continuous scientific feedback loop.

Chemistry World Model

Deep Research

Possibilities

Reaction Virtualisation

Prediction

Optimization

Explanation

Laboratory

Reality

Experimental Evidence

An experiment never simply ends a workflow. It makes the next decision better.

Chemistry-first intelligence

Built around chemistry, not a language model.

01

Chemical context

Reasons about molecular structure, reactions, conditions, and behaviour together. Not text.

02

Physics-informed prediction

The Virtual Reactor reasons from thermodynamic, kinetic, and molecular signals to evaluate how a reaction will behave.

03

Experimental feedback

Lab results feed back in, sharpening the next prediction.

04

Specialised reasoning

Each scientific question goes to a purpose-built reasoner, not one general-purpose agent.

The result

From chemical possibility to scientific confidence.

Scientific understanding+Reasoning+Prediction+Experimental evidence=Scientific confidence

Three reasoners, one loop. Deep Research finds the routes, Reaction Virtualisation predicts them, Optimization learns from what the bench actually did, and every result sharpens the next prediction.