VASP2KP

an open-source package to construct the $k\cdot p$ Hamiltonian and Zeeman's coupling and to compute the $k\cdot p$ parameters and Landé g-factors automatically from ab-initio calculations.

Current features

vasp2mat : compute matrix representations of the generalized momentum operator $\hat \pi$ , spin operator $\hat s$ , time reversal operator $\hat T$ and crytalline symmetry operators $\hat R$ on the DFT wavefunctions. The matrix elements of the operators are derived comprehensively and computed correctly within the Projector Augmented Wave method.
mat2kp : obtain the unitary transformation $U$ that rotates the DFT basis towards the standard basis, and then automatically compute the $k\cdot p$ parameters and g-factors. The obtained effective masses and g-factors are important and comparable with experimental observations.

Papers using VASP2KP

5. Yao, Jingyu, et al. "Axion insulator, Weyl points, quantum anomalous Hall effect, and magnetic topological phase transition in Eu 3 In 2 As 4." Physical Review B 111.4 (2025): L041117.

4. Yao, Jingyu, et al. "Excitonic Instability in Ta2Pd3Te5 Monolayer." Chinese Physics Letters 41.9 (2024): 097101.

3. Wang, Minxuan, Xiaoyu Wang, and Oskar Vafek. "Phase diagram of twisted bilayer MoTe 2 in a magnetic field with an account for the electron-electron interaction." Physical Review B 110.20 (2024): L201107.

2. Zheng, Pengyu, et al. "Spin Hall effect and topological surface states in a cubic Laves phase superconductor." Physical Review B 110.7 (2024): 075124.

1. V Cassiano, João Victor, et al. "DFT2kp: Effective kp models from ab-initio data." SciPost Physics Codebases (2024): 025.

Citing VASP2KP

If you are using this package, please cite the following work:

Zhang, Sheng et al. " $k\cdot p$ models and Landé g-factors from ab-initio calculations." Chin. Phys. Lett. 40, 127101 (2023).

Other relevant references to cite

If you use our package you will cite VASP and the other relevant DFT references. Additionally, our package relies on the following packages:

IRVSP: IRVSP is an open-source program, to compute irreducible representations of electronic states for all 230 space groups with an interface to the Vienna ab-initio Simulation Package.
IR2PW: IR2PW is an open-source program, to compute irreducible representations of electronic states for all 230 space groups with an interface to the Quantum Espresso package (PWscf).
kdotp-generator: kdotp-generator is used to automatically generate $k\cdot p$ effective Hamiltonians.

Therefore, please also cite these references: