[Pw_forum] Questions about a soft Raman active phonon

[Lijun Zhang]

Dear all,
  I am doing some calculations on the phase transition induced by lattice 
  instability. With increasing pressures, I found that a Raman active phonon 
  softens to zero, the same as behaviors in the ferroelectricity.  An elastic 
  instability also appears upon compression, signaled by a sound velocity 
  going to zero. However, the former extremely precedes the latter, thus I 
  conclude that the phase transition is driven by the phonon instability. Is it 
  right? If true, how to search for the stable high pressure phase through the 
  eigenvectors of the unstable mode?
  Any reply will be appreciated.     
  Lijun Zhang

		
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 Mp3疯狂搜-新歌热歌高速下   
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