CHEM In the literature: open

Predictive photochemistry through conical intersections in solution and proteins

In plain words

After absorbing light, a molecule often returns to its lowest energy state through a conical intersection (a point where two electronic energy surfaces touch), and this step decides what product forms. Simulations can follow this in isolated molecules, but predicting yields and timings for molecules in liquids or proteins from first principles is not yet reliable.

Precise statement

For benchmark photoreactions in condensed phases (retinal isomerization in rhodopsin, quantum yield about 0.65; azobenzene and stilbene isomerization in solvents; thymine relaxation in water), predict product quantum yields within 0.05 and excited-state lifetimes within 20 percent using an electronic-structure method accurate near conical intersections, an atomistic environment, and a nuclear dynamics method with controlled decoherence and nuclear quantum errors. An answer is a protocol meeting these targets in blind tests, or an identification of which approximation (electronic structure, environment, or dynamics) dominates the error.

What would settle it

Blind predictions of quantum yields and lifetimes for several condensed-phase photoreactions, released before transient-absorption or ultrafast-diffraction measurements, that meet the stated tolerances.

Status in the literature

Unverified note

The 2024-2026 cyclobutanone prediction challenge in the Journal of Chemical Physics compared blind gas-phase simulations with ultrafast electron diffraction and showed method-dependent spread; no comparable blind test exists for condensed phases.