Mistral has demonstrated its Large 4 model creating an interactive quantum chemistry simulator from a short prompt. According to the company, the model wrote the computational program, checked its numerical results and connected the calculation to a 3D visualization of a molecule breaking apart.
From bond selection to energy calculations
According to Mistral, the prompt left the model, nicknamed Le Chonk, to choose both the chemical bond to stretch and the molecular orbitals to display. In the demonstrated workflow, it then ran calculations for different bond lengths and checked whether the resulting energies converged and behaved plausibly.
The calculation used the Self-Consistent Field (SCF) method, which approximates a molecule’s electronic structure. It progressively refines an estimate of electron density until both the energy and density converge.
A slider updates the molecule and energy plot
Mistral’s demonstration included an energy plot and a view of orbitals moving onto separate molecular fragments as the bond stretched. A slider updated the geometry, orbital display, bond rendering and energy plot together.
The demonstration documented one successful run, leaving repeatability, failure rates and the numerical accuracy of the results unresolved.
Model capabilities and evaluation results
Large 4 uses a mixture-of-experts architecture with approximately 1.05 trillion parameters, of which approximately 52 billion are active per token. It accepts text and images, produces text and code, and supports a context window of up to 1 million tokens.
The model offers three reasoning modes designed to balance quality, response latency and token use. In DataCamp’s broader evaluation, Large 4 placed 32nd among 44 models on the aggregate index; the evaluator reported stronger results in cybersecurity and legal tasks and a middle-of-the-pack result in finance.
API access and self-hosting
Large 4 is available through Mistral Studio and the Mistral API. FP8 weights are also available on Hugging Face for self-hosting. The API costs $0.70 per million input tokens and $2.10 per million output tokens.
The license permits access to the weights and local deployment. Companies that want to offer Large 4 as a commercial cloud service need a separate agreement with Mistral.
