Linear response and force constants
Posted: Sun Dec 09, 2012 8:59 am
Hello all,
I'm trying to use linear response in VASP to compute force constants in real space. However, 2 things remain unclear to me.
1) I believe that linear response does not require a supercell approach to obtain force constants, contrary to the frozen phonon method. Is this statement correct?
2) I believe VASP gives the dynamical matrix at the gamma-point in vasprun.xml under the header "hessian". Does anyone know how to get dynamical matrices at other q-vectors from this and how to get force constants?
Thanks,
Maarten
I'm trying to use linear response in VASP to compute force constants in real space. However, 2 things remain unclear to me.
1) I believe that linear response does not require a supercell approach to obtain force constants, contrary to the frozen phonon method. Is this statement correct?
2) I believe VASP gives the dynamical matrix at the gamma-point in vasprun.xml under the header "hessian". Does anyone know how to get dynamical matrices at other q-vectors from this and how to get force constants?
Thanks,
Maarten