Questions tagged [lattice-dynamics]

Questions related to the lattice dynamics of solids.

Filter by
Sorted by
Tagged with
18 votes
2 answers
1k views

How to deduce phase transitions from a phonon calculation?

I came across the concept of using phonons to establish a material's dynamical stability, based on whether or not imaginary frequencies are present in its phonon band structure. What I am struggling ...
koroma's user avatar
  • 283
15 votes
2 answers
1k views

What does it mean to say a material is 'anharmonic'?

I understand that a harmonic picture of the potential in a material isn't enough to study lattice dynamics thoroughly. The quasi-harmonic approximation is a good workaround and helps incorporate ...
Hitanshu Sachania's user avatar
9 votes
1 answer
254 views

Is there an upper limit of temperature after which the quasi-harmonic approximation (QHA) fails?

I can't seem to articulate what made me ask this question but it sprang up when I asked: What does it mean to say a material is 'anharmonic'?. I've heard before that the electronic entropy ...
Hitanshu Sachania's user avatar