HyDRA II Blind Challenge

HyDRA is a blind prediction challenge to establish the predictive power of computational spectroscopy for small complexes of organic molecules with water. The quantity to predict is the hydrogen-bonded OH bond stretching fundamental of water relative to the free water value of 3657 cm^-1 (experimental symmetric stretch). You can read more about the challenge on our flyer.

The official start of HyDRA II was on the 16.09.2025, the submission deadline for predictions was on 20.03.2026. The preprint on the experimental results (written without knowledge of the computational predictions, published 30.03.2026) is available here: https://doi.org/10.26434/chemrxiv.15001373/v1. For more details on the HyDRA database and challenge series, see https://qmbench.net/.