Liquid-liquid phase coexistence in gold clusters. 2D or not 2D?

The thermodynamics of gold cluster anions (Au_N , N = 11, . . .,; 14) is investigated using quantum molecular dynamics. Our simulations suggest that Au_N may exhibit a novel, freestanding planar liquid phase which dynamically coexists with a normal three-dimensional liquid. Upon cooling with experimentally realizable cooling rates, the entropy-favored three-dimensional liquid clusters often supercool and solidify into the wrong dimensionality. This indicates that experimental validation of theoretically predicted Au_N ground states might be more complicated than hitherto expected.