The Pressure Effects on Electronic Structure of Iron Chalcogenide   Superconductors FeSe$_{1-x}$Te$_x$
  We study the electronic structure of iron-based superconductors FeSe$_{1-x}$Te$_x$ within the density functional theory. We pay particular attention to the pressure effects on the Fermi surface (FS) topology, which seem to be correlated with a critical superconducting temperature TC of iron chalcogenides and pnictides. A reduction of the FS nesting between hole and electron cylinders with increasing pressure is observed, which can lead to higher values of TC . The tellurium substitution into selenium sites yields FS changes similar to the pressure effect. 
A. Ciechan, M. J. Winiarski and M. Samsel-Czeka{\l}a
cond-mat.supr-con