transM
A small code for calculating temperature and doping dependent transport effective mass and thermoelectric electronic fitness function
transM calculates the transport effective mass for arbitrary semiconductors using output from BoltzTraP. It also calculates the thermoelectric electronic fitness function. This is an easy and general way to get the effective mass of a semiconductor from electronic structure calculations. It computes the inverse effective mass tensor for anisotropic materials.
The electronic fitness function measures the decoupling between conductivity and thermopower for arbitrary band structures, and may be useful for screening semiconductors as thermoelectrics. The transport effective mass calculation may be useful in screening semiconductors in relation to conductivity. Neither of these calculations makes assumptions about the nature of the band structure, and therefore this is applicable to high throughput searches, e.g. Z. Ran, et al., npj Computational Materials 4, 14 (2018). Both the electronic fitness function and the transport effective mass are doping and temperature dependent.
The thermoelectric fitness function is described in G. Xing, J. Sun, Y. Li, X. Fan, W. Zheng and D.J. Singh, Phys. Rev. Mater. 1, 065405 (2017); erratum ibid. 1, 079901 (2017).
The code is written in FORTRAN. It can be downloaded as a FORTRAN program along with a quick start guide, or as a gzipped tar file containing the program, quickstart, a static compiled version that may work on some linux machines and several examples. It requires a completed transport calculation using BoltzTraP as input.
The gzipped tar file can be unpacked using:
gunzip transM.tar.gz
tar -xvf transM.tar
This is free code, released under the creative commons CC-BY 4.0 license. You may use, modify and redistribute it as you see fit provided that you acknowledge the source.
The code was slightly updated on August 20, 2021 to work when the volume is not present in the outputtrans file, which is the case for some BoltzTraP interfaces. It will now prompt for the unit cell volume in bohr**3 instead of giving an error message in that case.
Downloads:
Contact: David J. Singh, david.joseph.singh@gmail.com