Skip to main content

Questions tagged [q-points]

For questions regarding $\mathbf{q}$-points in the Brillouin zone of phonon calculations.

Filter by
Sorted by
Tagged with
4 votes
0 answers
75 views

Creating a QPOINTS File for Phonon Calculations in VASP

How to construct a QPOINTS file for phonon calculations in VASP, and when is it employed instead of KPOINTS during a VASP standard run for phonon calculations? Could anyone also provide the preferred ...
5 votes
1 answer
250 views

VASPKIT and SeeK-path recommend different paths. Which one to choose?

I want to get the phonon density of states for a monolayer MoS2. For this, I need phonon dispersion curves, and to choose a path where to compute phonons. VASPKIT recommends Γ-M-K-Γ SeeK-path ...
4 votes
0 answers
67 views

q-points weighting factor in QE [closed]

When using Quantum Espresso to perform phonon calculations, one can specify a grid of q-point using ldisp=.true. (Monkhorst-Pack grid) If I ask for a AxBxC grid, the code will reduce this grid taking ...
7 votes
1 answer
148 views

Can we translate vibrational frequencies at q-points to vibrational frequencies of atoms?

Lattice dynamics codes like phonopy output vibrational frequencies at q-points. Can we get data of vibrational frequencies for each of the atoms in the supercell? (...
6 votes
0 answers
161 views

Odd/even q-point mesh in harmonic phonon density of states (DoS) calculations [closed]

Total DoS for two different q-point grids, $100\times100\times100$ and $101\times101\times101$, are graphed above. The DoS for $63\times63\times63$, $65\times65\times65$, $71\times71\times71$, $72\...
6 votes
1 answer
1k views

Best practice(s) for q-points convergence in phonon density of states calculations

The answer can be a complete description of all the things we must be attentive to while converging q-points. A peculiar thing that I feel contradicted about: Generally, we don't take an equal # of k-...
8 votes
1 answer
594 views

Should all q-points in the first Brillouin zone be sampled in phonon density of states calculations?

For electronic density of states (DoS) calculations with VASP, it is recommended that VASP's internal symmetry routine is turned ...