Ice XXI and XXII Take Center Stage in Water’s Complex Phase Parade
Using high-pressure experiments and advanced imaging, researchers observed ice XXI and ice XXII—the most complex ice phases yet—alongside metastable states that illustrate Ostwald’s step rule; simulations once predicted tens of thousands of possible ice forms, but only a subset emerge in reality, revealing new insights into water’s behavior under extreme conditions and potential relevance to icy worlds and drug stability.
