  The existence of a body centered tetragonal phase of Cu has been investigated
in this manuscript when the single crystal FCC Cu is subjected to both high
pressure and high temperature. The results have been demonstrated through DFT
calculations (which are typically done at 0 K) followed by Helmholtz free
energy calculations (for high temperature). The new metastable phase of Cu
demonstrates higher thermal conductivity compared to that of the FCC phase and
thereby may be beneficial for high temperature engineering applications.
