AICON: A program for calculating thermal conductivity quickly and accurately

Abstract

AICON (Ab Initio Conductivities) is a program written in Python for computing lattice thermal conductivity of crystalline bulk materials using the modified Debye–Callaway model. Building upon the traditional Debye–Callaway theory, the modified model obtains the lattice thermal conductivity by averaging the contributions from acoustic and optical branches based on their specific heat. The only inputs of this program are the phonon spectrum, phonon velocity and Grüneisen parameter, all of which can be calculated using third-party ab initio packages, making the method fully parameter-free. This leads to a fast and accurate evaluation and enables high-throughput calculations of lattice thermal conductivity even in large and complex systems. In addition, this program calculates the specific heat and phonon relaxation times for different scattering processes, which will be beneficial for understanding the phonon transfer behavior. Program summaryProgram Title: AICONProgram Files doi:http://dx.doi.org/10.17632/s9b8y8t92c.1Licensing provisions: GNU General public license 3Programming language: Python3External routines/libraries: Numpy, Scipy, spglib, pymatgenNature of problem: The calculation of lattice thermal conductivity from first principles with an anharmonic approximation requires a large number of calculations to construct the third-order force constants matrix, which could be prohibitively long time.Solution method: Modified Debye–Callaway model, where only the phonon spectrum, phonon velocity and Grüneisen parameter are needed. The acoustic branch and optic branch are both considered to obtain the final lattice thermal conductivity.