Electron-temperature dependent parameters: electron-phonon coupling (G), electron heat capacity (Ce), and electron heat conductivity (Ke), calculated with XTANT-3 code

The electron-ion (electron-phonon) coupling parameter, electronic heat capacity, and electronic heat conductivity as functions of the electronic temperature (Te) were calculated with the help of the nonperturbative dynamical coupling formalism and Kubo-Greenwood method. The method was implemented in the XTANT-3 code (https://github.com/N-Medvedev/XTANT-3). When using this dataset, please, cite the corresponding papers listed below.

Materials included – fcc metals: Al, Ca, Ni, Cu, Sr, Y, Zr, Rh, Pd, Ag, Ir, Pt, Au, and Pb; hcp metals: Mg, Sc, Ti, Co, Zn, Tc, Ru, Cd, Hf, Re, and Os; bcc metals: V, Cr, Fe, Nb, Mo, Ba, Ta, and W; other metals: Sn, Ga, In, Mn, Te, and Se; semimetal graphite; semiconductors – group IV: Si, Ge, and SiC; group III-V: AlAs, AlP, GaP, GaAs, and GaSb; oxides: ZnO, TiO2, and Cu2O; and others: PbI2, ZnS, and B4C; and 2d carbon-based materials.

The electronic heat capacity, Ce(Te), as a function of the electronic temperature (Te), is in the files named

• Ce_[El]_[data].txt with [El] being the chemical element; [data] being additional information such as the structure of the material, or the tight-binding parametrization used (e.g., DFTB) (if the parametrization is not listed, the default NRL parametrization is used for metals, but various ones for semiconductors).

First two or three lines, starting with the symbol '#' are commenting the columns and the units of the variables in them. The columns contain:

1. Electron temperature in [K]
2. Electronic heat capacity [J/(m^3 K)]

The data for metals, semiconductors [1], and 2d-carbon materials [2], are stored in the following directories, respectively:

• Ce_metals
• Ce_semiconductors
• Ce_2d_materials

Note #1: not all materials, for which the coupling parameter is present, may have a file with the electron heat capacity. A separate set of heat capacities is present in the files with the heat conductivity, see below.

Note #2: for 2d-materials, the two-dimensional electronic heat capacity is in the units of [J/(m^2 K)]. The heat capacity may be converted into 3d units, if needed, assuming the layer thickness of 3.35 A.

The electron-ion (electron-phonon) coupling parameters, G_e-ph(Te), as a function of the electronic temperature (Te), are in the files are named as follows:

• G_e-ph_[El]_[data].txt with [El] being the chemical element; [data] being additional information, such as the structure of the material, or the tight-binding parametrization used (e.g., DFTB) (if the parametrization is not listed, the default NRL parametrization is used for metals, but various ones for semiconductors).

The data for elemental metals [3] (and SiAl alloy [4]), semiconductors [1], and 2d-carbon materials [2], are stored in the directories named, respectively:

• G_e-ph_metals
• G_e-ph_semiconductors
• G_e-ph_2d_materials

The files use the following format: First two or three lines, starting with the symbol '#' are commenting the columns and the units of the variables in them. The columns contain:

1. Electron temperature in [K]
2. Electron-ion coupling in [W/(m^3 K)]

Note #3: in some files there are multiple columns for various atomic temperatures, listed in the third commentary line

Note #4: the start and end of the grid of the electronic temperature are not fixed but differ in various files

Note #5: For 2d materials, the two-dimensional electron-ion coupling parameter is in the units of [W/(m^2 K)]. It may be converted into 3d units, if needed, assuming the layer thickness of 3.35 A.

The electronic heat conductivity data are stored in the files named:

• K_[El]_[data].txt with [El] being the chemical element; [data] being additional information, such as the structure of the material, or the tight-binding parametrization used (e.g., DFTB) (if the parametrization is not listed, the default NRL parametrization is used for metals, but various ones for semiconductors).

The data for metals and semiconductors [5] are stored in the directories named, respectively:

• K_metals
• K_semiconductors

First two lines, starting with the symbol '#' are commenting the columns and the units of the variables in them. The columns contain:

1. Electron temperature in [K]
2. Total electronic heat conductivity in [W/(m K)]
3. Electron-phonon term in electronic heat conductivity in [W/(m K)]
4. Electron-electron term in electronic heat conductivity in [W/(m K)]
5. Electronic chemical potential [eV]
6. Electronic heat capacity in [J/(m^3 K)]

Note #6: the electronic heat capacity in these files is calculated differently from that in the files 'Ce [El] [data].txt' above. In this section, it is calculated for the ideal crystal structure averaged over 7x7x7 k-points [5]; whereas the Electron-Heat-Capacity section was obtained in dynamical simulations at a given atomic temperature in the gamma-point [1,2].

Although we endeavour to ensure that the code XTANT and results delivered are correct, no warranty is given as to their accuracy. We assume no responsibility for possible errors or omissions. We shall not be liable for any damage arising from the use of these dataset, or from any action or decision taken as a result of using it or any related material. This dataset is distributed as is for non-commercial peaceful purposes only, such as research and education (for details, see GPL-3.0 license).

[1] N. Medvedev, "Electron-phonon coupling in semiconductors at high electronic temperatures" Phys. Rev. B 108, 144305 (2023) https://doi.org/10.1103/PhysRevB.108.144305

[2] N. Medvedev, I. Milov, B. Ziaja, "Structural stability and electron‐phonon coupling in two‐dimensional carbon allotropes at high electronic and atomic temperatures" Carbon trends 5, 100121 (2021). https://doi.org/10.1016/j.cartre.2021.100121

[3] N. Medvedev, I. Milov, "Electron-phonon coupling in metals at high electronic temperatures", Phys. Rev. B. 102 (2020) 064302 https://doi.org/10.1103/PhysRevB.102.064302

[4] N. Medvedev, I. Milov, "Contribution of inter- and intraband transitions into electron–phonon coupling in metals", Eur. Phys. J. D 75, 212 (2021)https://doi.org/10.1140/epjd/s10053-021-00200-w

[5] N. Medvedev, F. Akhmetov, I. Milov, "Electronic heat conductivity in two-temperature state" Int. J. Heat and Mass Transfer 228, 125674 (2024) https://doi.org/10.1016/j.ijheatmasstransfer.2024.125674