Unusual lone pairs in tellurium and their relevance for superconductivity

When pairs break up: Ab initio calculations are used to quantitatively characterize the stability and shape of an unusual type of lone pair in tellurium. By comparing the calculated band structures for tellurium under ambient and high pressure, it is shown that the flat/steep-band condition necessary for superconductivity is created for the high-pressure modification Te-II through the delocalization and breakdown of the lone pairs (see scheme). (Figure Presented). © 2006 Wiley-VCH Verlag GmbH & Co. KGaA.