This document describes the format of the output NetCDF file generated by the interpolation code: ndb.dVbare.
ndb.dVbare
The ndb.dVbare file is generated when the write_dVbare option is enabled. It contains the interpolated local part of the bare potential change, along with phonon data on the fine grid.
Dimensions
| Dimension Name |
Description |
nq |
Number of interpolated q-points. |
nmodes |
Number of phonon modes. |
Nx |
FFT grid dimension along the first lattice vector. |
Ny |
FFT grid dimension along the second lattice vector. |
Nz |
FFT grid dimension along the third lattice vector. |
re_im |
Complex number components (2: Real, Imaginary). |
atom |
Number of atoms in the unit cell. |
pol |
Polarization direction (3 for x, y, z). |
Variables
Local Potential
| Variable Name |
Type |
Dimensions |
Description |
dVbare_local |
float |
[nq, nmodes, Nx, Ny, Nz, re_im] |
Peroidic part of local part of the change in the bare potential \(e^{-\mathbf{q}\cdot \mathbf{r}}\partial_{\mathbf{q}\nu} V_{loc}(\mathbf{r})\) on the real-space FFT grid for each mode \(\nu\) and q-point. |
Phonon Data (Interpolated)
| Variable Name |
Type |
Dimensions |
Description |
FREQ |
float |
[nq, nmodes] |
Interpolated phonon frequencies on the fine grid (in Ry). |
POLARIZATION_VECTORS |
float |
[nq, nmodes, atom, pol, re_im] |
Interpolated phonon polarization (displacement) vectors, which are defined as \(u_{\kappa \alpha}^{\nu} = \frac{1}{\sqrt{M_{\kappa}}} e_{\kappa \alpha}^{\nu},\) where \(e_{\kappa \alpha}^{\nu}\) is the eigenvector of the dynamical matrix corresponding to phonon mode \(\nu\), \(\kappa\) labels the atom in the unit cell, \(\alpha\) denotes the Cartesian direction, and \(M_{\kappa}\) is the mass of atom \(\kappa\). |
Grid Info
| Variable Name |
Type |
Dimensions |
Description |
qpoints |
float |
[nq, pol] |
List of interpolated q-points (in reduced coordinates). |