1. About
1.1 What is GiftBTE?
GiftBTE is a powerful tool designed to investigate submicron heat conduction. At the submicron scale, the characteristic length of heat conduction becomes comparable to the phonon mean free path, rendering the macroscopic Fourier’s law inapplicable. Instead, at this scale, the phonon Boltzmann transport equation accurately describes heat conduction. GiftBTE employs numerical methods to solve this equation and simulates submicron heat conduction. It takes phonon properties from first-principles simulations as input and provides a built-in database for some materials. Additionally, GiftBTE offers an interface with two external unstructured mesh generators. The tool is easy to use, as it only requires an environment with g++, MPI, and Cmake.
Video Links (in Chinese): GiftBTE软件教程-1:软件简介
1.2 Features
General
- Deterministic solver of phonon Boltzmann transport equation 
- Applicable to any crystalline materials and structures 
- Applicable to steady-state and transient problem 
- Interface to ShengBTE, ALAMODE, GMSH, COMSOL, and Paraview packages 
- Mainly written in C++, parallelized in MPI 
Applications
- Computing thermal conductivity of nanostructures such as nano-porous media, superlattice, nanowires, nano-composite 
- Predicting temperature rise in transistors 
- Simulating laser heating process 
- Other submicron heat conduction problems 
WorkFlow

Code structure
1.3 Links
- Documentation: https://bte.sjtu.edu.cn/ 
- Git repository: https://github.com/Gift-BTE-developer/Gift-BTE.git 
1.4 License
This software is distributed under the GNU General Public License v3.0 license. See the LICENSE.txt file for license rights and limitations.
1.5 How to cite GiftBTE
Please cite the following papers when you use GiftBTE:
Yue Hu, Ru Jia, Jiaxuan Xu, Yufei Sheng, Minhua Wen, James Lin, Yongxing Shen, Hua Bao, GiftBTE: An efficient deterministic solver for non-gray phonon Boltzmann transport equation, J. Phys.: Condens. Matter (2023). https://doi.org/10.1088/1361-648X/acfdea.
Hu, Yue, Yongxing Shen, Hua Bao, Ultra-efficient and parameter-free computation of submicron thermal transport with phonon Boltzmann transport equation, Fundamental Research (2022). https://doi.org/10.1016/j.fmre.2022.06.007.
1.6 Issues & Bug report
- If you find a bug or issue related to GiftBTE, please report it at Github Issues 
- Other questions and suggestions can be posted on the Github Disccusions 
In either case, please search for the previous questions and read the FAQ page of this document before asking.
1.7 Acknowledgment
This project is/was partially supported by the following projects:
- National Key R & D Project from Ministery of Science and Technology of China (Grant No. 2022YFA1203100) 
- National Natural Science Foundation of China (Grant No. 52122606) 
1.8 Contributors & Contact
Authors: Yue Hu, Ru Jia, Jiaxuan Xu, Yufei Sheng, Minhua Wen, James Lin, Yongxing Shen, Hua Bao*
Mr. Peng Wan (Center for High Performance Computing, Shanghai Jiao Tong University) is the main contributor to the GPU version of GiftBTE
TPEC Lab (Contact: Gift-BTE@outlook.com)
Website: https://sites.ji.sjtu.edu.cn/hua-bao/
Global Institute of Future Technology (GIFT)
Shanghai Jiao Tong University
China