Guan package

Guan is an open-source python package developed and maintained by https://www.guanjihuan.com/about (Ji-Huan Guan, 关济寰). With this package, you can calculate band structures, density of states, quantum transport and topological invariant of tight-binding models by invoking the functions you need. Other frequently used functions are also integrated, such as machine learning, file reading and writing, figure plotting, data processing and AI chat.

The primary location of this package is on https://py.guanjihuan.com.

Installation

pip install --upgrade guan

Usage

import guan

Summary of API Reference

• basic functions
• Fourier transform
• Hamiltonian of examples
• band structures and wave functions
• Green functions
• density of states
• quantum transport
• topological invariant
• machine learning
• file reading and writing
• figure plotting
• data processing
• AI chat
• decorators
• others

About this package

• The original motivation of this project is for self use. Based on this project, the frequent functions can be imported by “import guan” instead of repeated copies and pastes. You can also install and use this open-source package if some functions are helpful for you. If one function is not good enough, you can copy the Source Code and modify it. You can also feed back to guanjihuan@163.com. The modifications and supplements will be in the following updated version.
• Most realizations of this package are only based on functions, which are concise and convenient. The boring document is omitted and you have to read the Source Code for details if it is necessary. Nevertheless, you don’t have to be worried about the difficulty, because all functions are simple enough without too many prejudgments and the variable names are written commonly as far as possible for the easy reading.
• Before the function calling in your project, you are recommended to briefly read the Source Code to know the specific formats of input and output about the function. Applying functions mechanically may cause errors. Notice that as the package is developed, the function names may be changed in the future version. Therefore, the latest API Reference is important and helpful.

Citation

There is no official paper related to this package temporarily, but you can cite one or all of the following papers instead, which are the motivation of this project, if this package is greatly helpful for your research.

• Ji-Huan Guan, Wen-Kai Lou, and Kai Chang, Topological hidden phase transition in honeycomb bilayers with a high Chern number, Phys. Rev. B 110, 165303 (2024).
• Ji-Huan Guan, Yan-Yang Zhang, Si-Si Wang, Yan Yu, Yang Xia and Shu-Shen Li, Barrier Tunneling and Loop Polarization in Hopf Semimetals. Phys. Rev. B 102, 064203 (2020).
• Ji-Huan Guan, Yan-Yang Zhang, Wei-Er Lu, Yang Xia and Shu-Shen Li, Barrier tunneling of the loop-nodal semimetal in the hyperhoneycomb lattice. J. Phys.: Condens. Matter 30, 185402 (2018).