Keyword "cell" determines geometry of the cell. Note that currently only the orthorhombic cells are supported, thus for the fcc crystal, one has to specify a conventional cubic cell (defined in this example by 1. 1. 1.). Keyword "species" determines a list of atomic species in the system, 1 being the number of different species. In this example, there is only one type of atoms, Ar, with mass 40 a.u. and charge of zero electrons. Keyword "lattice" determine the lattice constant at which simulations will be performed. "exp-6" is one of the available pair-wise potentials, so this keywords determines interactions between the atoms. "natoms" defines number of atoms in the cell, and "fractional" means that fractional coordinates of the atoms will be supplied. "end" specifies the end of the file.
Executing PhonTS in this directory should generate the following screen output:
screen output | Mirrors the input parameters specified in phonons_input.dat, as well as default parameters of the simulations. Reports thermal conductivity. |
pdos.dat | Reports phonons density of states. First three coloumns is the energy in different units (THz, cm^{-1} and meV), 4th coloumn is the density of states as calculated, and the 5th one is density of states smoothed out by the gaussian lineshape. |
tc_dos.dat | This file contains spectral thermal conductivity (contribution to thermal conductivity from phonons in the frequency interval) for xx, yy and zz components. Its calculation is similar top phonon density of states calculations, thus raw data typically contains unphisical sharp spikes due to relatively coarse grid. PhonTS therefore spoothes it out using the same gaussian smoothing as for the PDOS. First coloumn is the frequency in THz, folloed by xx component raw data, then smoothed out, then the same for yy and zz components. Each temperature has its own block. |
phon_lifetimes.dat | Here we have phonons lifetimes in picoseconds as a function of the k-point and temperature. For each k-point (specified by a number and k_{x},k_{y},k_{z}) there are 3N lifeitimes which correspond to 3N phonons at this k-point, where N is the number of atoms. |
eigenvectors.dat | This file contained phonons eigenvectors. The format of the file is first column specifies the eigenvector at given k-point, the second specifies the component of the eigenvetor, followed by real and imaginary part of the value. The k-point number is the last number in the line. |
scatt.dat | This file contains the scattering amplitudes map, which essentially shows with which phonons a phonon at particular frequency interact the most. It is a 3D data, with x and y (first two coloumns) being the energy of the original phonon and phonons it scatters into, while the following 3 coloumns samples the amplitude of different scattering processes. The last 3 coloumns have the same data but smoothed out by gaussians. There are as many blocks of data as there are temperature points. |
freq.dat | |
group_vel.dat |