Title  
Chemical bonding and Born charge in 1T-HfS2

Suggested Citation  
Neal, Sabine N; Li, Shutong; Birol, Turan; Musfeldt, Janice L. (2021). Chemical bonding and Born charge in 1T-HfS2. Retrieved from the Data Repository for the University of Minnesota, https://doi.org/10.13020/jyp2-qd29. 

Published Date  
2021-04-09

Author Contact  
Li, Shutong (li000269@umn.edu)

Authors 
Neal, Sabine N 
Li, Shutong 
Birol, Turan 
Musfeldt, Janice L 

Abstract 
We combine infrared absorption and Raman scattering spectroscopies to explore the properties of 1T-HfS2- a heavy transition metal chalcogenide with strong spin-orbit coupling due to incorporation of the 5d center. We employ the LO-TO splitting of the Eu mode along with a reevaluation of mode mass, unit cell volume, and dielectric constant to reveal the Born effective charge. We find ZB*= 5.33e, in excellent agreement with complementary first principles calculations. In addition to resolving controversy over the nature of chemical bonding in this system, we decompose the Born charge into polarizability and local (ionic) charge. We find α= 5.07 Å3 and Z*= 5.19e, respectively. In order to understand how ZB* relates to the nominal 4+ charge of the Hf center, we decompose the theoretical Born effective charge into band-by-band contributions, and find that polar displacement-induced charge transfer from sulfur p to hafnium d orbitals is responsible for the enhancement of Born charge. 1T-HfS2 is thus an ionic crystal with strong and dynamic covalent effects.

Description  (from readme.md) 
# HfS2_results
This is a repository for the calculation results of the paper 'Chemical bonding and Born charge in 1T-HfS$_2$'. 
The calculation is mainly done with Vienna Ab initio Simulaton Package and Wannier90. Reach to the author for more details of the calculations.
Three main folders are included:
band: data for band plot.
born: data for Born effective charge calculations.
wannier: data for wannier90 calculations.
Two main parts of simulations are included in this dataset: 1. Density functional theory: the input and output for Vienna Ab-initio Simulation Package (VASP) used in this publication, which include: POSCAR: Crystal structure files. INCAR: Input parameters. KPOINTS: Input parameters (for k-mesh). VASPRUN.XML: A formatted output. 2. Wannier function: the input and output for Wannier90, which includes: wannier90.win: Input parameters. wannier90.wout: A formatted output.

Funding information 
Sponsorship: The work at the University of Minnesota is supported primarily by the National Science Foundation through the University of Minnesota MRSEC under Award Number DMR-2011401.

Related Publication  
Neal S N, Li S, Birol T, et al. Chemical bonding and Born charge in 1T-HfS $ _2$[J]. arXiv preprint arXiv:2104.00478, 2021. https://arxiv.org/abs/2104.00478

License  
CC0 1.0 Universal