Band structure and excitonic properties of WSe₂ in the isolated monolayer limit in an all-electron approach

This GitHub repository hosts the data files and related information for the research paper titled "Band structure and excitonic properties of WSe₂ in the isolated monolayer limit in an all-electron approach," authored by Niloufar Dadkhah and Walter R. L. Lambrecht, available on arXiv:2402.17924

Repository Structure

The repository is structured to provide easy access to the data files used in the figures of the paper. Below is a guide to the contents and organization:

1. Grace Files (Folder: agr)

• Description: Contains .agr for use with XMGRACE.
• Figures Covered: 2, 3, 4, 5.

Figure	agr file
Fig. 2	fig2.agr
Fig. 3	fig3.agr
Fig. 4	fig4.agr
Fig. 5	fig5.agr

2. xsf Files (Folder: xsf)

• Note: Available upon request. Email at nxd228@case.edu.
• Description: Includes xsf file format for visualization with VESTA or other visualization programs.
• Figure Covered: 8, 9.

Exciton label	vesta file
λ= 1,2	xcfh-w-1and2.vesta
λ= 3	xcfh-w-3.vesta
λ= 4	xcfh-w-4.vesta
λ= 5,6	xcfh-w-5and6.vesta
λ= 7,8	xcfh-w-7and8.vesta
λ= 21,22	xcfh-w-21and22.vesta

• Features: Enables users to explore the structure and exciton wavefunction data from various angles and at different sections and adjust isosurface values for exciton distributions.

3. Band Structure Data (Folder: bnds)

• Description: Contains ASCII files with band structure data relevant to figures 1 and 6.
• Data Format: Information on the number of bands, Fermi level, k-point labels, and energy eigenvalues. Details at Questaal Data Format.

line 2: number of points long first line
line 3: k-point coordinates in units 2pi/a  with a the lattice constant
lines 4 -40: energy eigenvalues  in Rydberg
line 5: next k-point followed by bands etc.
until end of line.

• Visualization: Data can be visualized using Questaal's plbnds tool or band-plot.py (included).
• Files Included: bnds.lda, bnds.rpa, bnds.bsw (representing different computational approximations).

Approximation	file
LDA	bnds.blue
QSGW	bnds.red
QSGW$\hat$	bnds.green

4. Meta Data

• Description: Provides the fundamental input files (ctrl.wse and site.wse) needed to generate all the dataset, alongside .rst, syml, and sigm files for the self-consistent potential restart data and the self-energy files.

5. h5 Files (Folder: h5)

• Description: Contains .h5 files to use for k-space visualiations of excitons.

• Figures Covered: 6, 8.

• Files Included:

  • w2q0e.h5 contains three data sets related to the two-particle BSE Hamiltonian. The dimensions of the BSE Hamiltonian is determined by:

    • 1- number of k-points used for the BSE calculation (specified by nkgw1, nkgw2, nkgw3 for three directions)
    • 2- number of valence bands (nv) and conduction bands (nc) used for the BSE calculation.
    • 3- number of spins (nspin). If the calculation is spin-polarized, nspin=2, else nspin=1.

  Then the number of eigenvectors (nw) and length of each eigenvector (lw) will be:.

  nw=lw=nkgw1*nkgw2*nkgw3*nv*nc
  

  Three data sets in w2q0e.h5 file are:

  Two-particle BSE Hamiltonian eigenenergies known as the exciton energies (ew):

   ew      Dataset {nspin, nw}
  

  Oscillator strength for each excitonic energies:

   rccr    Dataset {nq, nw}
   
  where nq is the number q-vector directions for which the oscillator strengths are calculated. By default the directions are (1,0,0) (0,1,0) (0,0,1) (1,1,1)
  

  Eigenvectors associated which each eigenenergy (w)

   w       Dataset {nspin, nw, lw}
   
   which are written in the row-major order.
  

  • bz.h5 k-point mesh data.

Additional Information

For more details on the paper and the corresponding research findings, please refer to the arXiv publication.

This repository aims to support the reproducibility of our research by providing comprehensive datasets and tools necessary for analysis. We encourage the use of these resources in academic and research settings.