Skip to main content

Thank you for visiting You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

Physical chemistry

Ice niceties

The molecules in ice crystals normally form a hexagonal lattice, which is why all snowflakes are six-sided (pictured). But on page 218, Lupi et al. report that the tiniest ice crystals prefer a different arrangement — a finding that has implications for climate models (L. Lupi et al. Nature 551, 218–222; 2017).

The authors used computational simulations to investigate how nanoscale ice crystals form from water. They found that a molecular arrangement consisting of randomly ordered layers of hexagonal and cubic arrays is the most thermodynamically stable arrangement in crystallites of up to 100,000 molecules.

The findings disagree with the classical theory of crystallite formation, which is used to predict the rates at which ice crystallites form in the atmosphere — a variable that influences cloud formation. The authors conclude that the classical theory must be corrected to improve climate and weather forecasts.

Footnote 1



  1. See all news & views


Rights and permissions

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Mitchinson, A. Ice niceties. Nature 551, 178 (2017).

Download citation

  • Published:

  • Issue Date:

  • DOI:


Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing