Interplay between structure and superconductivity: Metastable phases of phosphorus under pressure

Among elemental compounds, the high-pressure superconducting phase diagram of phosphorus is one of the most complex. Resistivity measurements and $a\phantom{\rule{0}{0ex}}b$ $i\phantom{\rule{0}{0ex}}n\phantom{\rule{0}{0ex}}i\phantom{\rule{0}{0ex}}t\phantom{\rule{0}{0ex}}i\phantom{\rule{0}{0ex}}o$ superconductivity calculations reported in this paper solve for the first time the open controversies on the anomalous superconducting trends; forming a single, consistent scenario of multiple metastable structures which coexist beyond their thermodynamical stability range. These metastable structures exhibit critical temperatures, which are distinctively higher than the putative ground-state structures, suggesting that the selective stabilization of metastable phases represents a viable strategy to improve superconductivity properties on conventional superconductors.