The math no LLM seems to run by default

Coulombic efficiency (CE) compounds. If a cell loses 0.5% of its usable charge every cycle, it doesn't lose 0.5% × 2,000 over the system's life. It loses 0.5% of whatever capacity remains at the start of each cycle. The arithmetic is brutal:

A 99.5% CE cell is effectively dead at cycle 45. The pitch said 2,000. Anyone who scaled that claim through a basic compounding calculation would have stopped reading.

Two prompts, one LLM, two opposite answers

I asked a major frontier LLM about this claim in two ways. The cell, the numbers, the chemistry - all identical. Only the framing changed.

The LLM glossed over the math. It read the framing as "this is good," and confirmed.

The math was always there. The LLM only ran it when the prompt explicitly demanded it.

Why this matters for due diligence

Pitch decks are written to sound impressive. A "99.5% CE over 2,000 cycles" claim, placed next to "excellent cycling stability" without context, reads as a strength to anyone - human or LLM - who isn't running the math from first principles.

A deterministic physics engine doesn't have this failure mode. The CE compound-decay rule is one of twelve constraints that fires on every claim, every time, regardless of how the claim is phrased. The math doesn't care about prompt framing.

Three takeaways for investors:

• Test your tools. Ask the same physics question two different ways. If you get two different answers, the tool isn't doing physics - it's doing pattern matching on language.
• Reframe everything. Before trusting any verdict on a technical claim, rewrite the claim in mathematical terms. If the verdict changes, the verdict was unreliable.
• The math is the moat. Anything that can be spin-doctored by a marketing copywriter shouldn't be the foundation of a 5-million-euro investment decision.

This is precisely why MatIntel uses LLMs only for extraction (reading the documents) and a 12-rule deterministic engine for the verdict. Same input, same verdict, every time - whether the founder writes "99.5% CE over 2,000 cycles" or "the cell loses 0.5% per cycle, compounded." The R6 cycle-life rule fires either way.

The question, in six different costumes

What they all actually want

They want three things, in this order:

• A verdict they can defend in a meeting that's already on the calendar.
• Citations they can quote if challenged ("according to 821 papers in the corpus, including 148 that directly confirm...").
• A resolution path if the verdict is ambiguous - what data point, costing what, on what timeline, would resolve the uncertainty.

Notice what is not on this list. They don't want a numeric "score." They don't want a market-size analysis. They don't want a recommendation to invest or not invest. They want the physics question answered, with the corpus behind it, so they can do the rest of their job.

The shared daily pain

Across all six, the same operational pain shows up:

Physics verification is expensive AND slow AND unreliable through the standard channels. A subject-matter advisor on GLG or Guidepoint costs €600-1,200/hr and requires 5-7 working days to schedule. An in-house PhD on retainer costs €15k+ per month and only covers their narrow domain. An LLM gives an answer in 12 seconds - but the answer changes when you rephrase the question (see last week's post by Joachim).

So the de facto choice is between expensive-and-slow, expensive-and-narrow, or fast-and-unreliable. None of the six readers is happy with that menu.

What we send back, regardless of who asked

The deliverable is the same for all six personas: a 2-document PDF in 48 hours.

The investment memo (3 pages) translates the physics into the investor's language: PROBLEM, RESOLUTION, RISK MATRIX, BUY/HOLD logic, references. The technical pre-screen (2 pages) shows the underlying physics check that produced the memo's verdict: each claim, the rule it triggered, the corpus evidence supporting or contradicting it, the resolution path if ambiguous.

A VC partner reads the memo and skims the pre-screen for IC defensibility. A procurement officer reads the pre-screen first and the memo for executive summary. The artifact is the same - the reading order changes.

What we don't do, and why it matters

I get asked, weekly, to extend the scope. Can you also assess the team? Can you validate the market size? Can you give us a valuation range? Can you predict whether they'll close their Series B in 18 months?

The answer is no, and the reason is in the value prop: we do one thing - physics verification of technical claims, against a 789K-paper corpus, in 48 hours, with a citable PDF as the deliverable. Everything else, you have other tools for. A focused tool beats a generalist tool, in due diligence as in most things.

If you're reading this and recognize yourself in one of the six cards above - that's the daily reality this product is built for. The free preliminary score on the home page is the simplest way to find out whether it would actually help your work.