How can I interpret an energy level that ovelap with both VBM and CBM in a band structure?

Dear All In the attached figure, which is a doped SnTe system, the Fermi level (Ef=10.123 eV) is found to cross the conduction band at the gamma point. It actually overlap with the highest...

02 October 2020 200 3 View

What should be the value of the total dipole moment of the CO2 molecule calculated by Quantum ESPRESSO?

I found the dipoles of CO2 calculated by Quantum ESPRESSO as : Computed dipole along edir(3) : Elec. dipole 0.3112 Ry au, 0.7909 Debye Ion. dipole...

01 May 2020 5,036 3 View

What software shall I use to build computer cluster? Do you know free software similar to OSCAR?

Dear All I am trying to build a computer cluster consisting of a master and some number of slave desktop computers, to increase the performance. I tried to use Open Source Cluster Application...

28 April 2020 5,399 2 View

Shall all the three criteria (etot_conv_thr, forc_conv_thr, cell) be satisfied to finish the relaxation calculation in Quantum Espresso?

Dear Sir I'm beginner for Quantum Espresso? I conducted this calculation using Quantum Espresso, but I observed that the final total energy is more than the etot_conv_thr but the total force...

01 February 2019 4,025 6 View

How can I produce Bayesian credible intervals for individual predictions for an exponential distance decay model?

I am trying to generate predictions for an exponential distance-decay model of a response variable (Y) varying with distance (D), i.e. Y = a*exp(-b*D). My problem is how to generate credible...

12 April 2014 665 4 View

Sample size and the reproducibility problem

The reproducibility problem widespread in many disciplines of science. The Editorial Board of The Journal of Neuroscience took a bold step. In the May 20, 2020 issue they wrote an illuminating...

01 January 1970 1,989 3 View

What could be the reason for not having further low chi square value (better agreement) in my refinement result?

I have tried every combination of parameter changes and after that i have a poor chi square value. I can't get it lower any further. I know there have been a lot of discussion about Rietveld...

26 February 2021 8,480 3 View

Why the CHi^2 is close to zero with a bad fitting but the Rp and Rwp are still high?

I am refining my XRD data using in FullProf program. The intensity of the modulated X-ray peaks is almost flat. I tried to adjust the peak intensities but unsuccessful. What is the reason? I guess...

23 February 2021 2,304 4 View

Rietveld refinement of cement paste?

I am a beginner in rietveld refinement, my samples contain numerous overlapped peaks and amorphous phases. I have few doubts related to rietveld refinement of cement paste: 1. My quantifications...

11 January 2021 8,873 6 View

When i accept card in "HighScore plus app" should i attention to cards quality (in Reitveld analysis)?

Hi I wanna use Reitveld analysis in my project but i have big question that is: Should i see quality of each card (or Not important !!?), or it is enough to check the score and scale factor of...

04 January 2021 7,750 1 View

Which analysis method in XRD analysis is the most accurate way to measure crystallite size & lattice starin? Scherrer, Williamson-Hall or Rietveld?

Here are three different ways to calculate crystallite size and lattice strain of a sample, based on XRD peaks: "Scherrer" calculation, "Williamson-Hall" or "Rietveld". Each calculation is proper...

04 January 2021 7,836 4 View

How could I fix the "negative intensities in scan data points" error in X'pert when applying Rietveld analysis?

I have faced a problem in using Xpert in Rietveld Analysis, I got the abovementioned message when trying to run Rietveld analysis. The cause of the problem is probably due to that the spectrum has...

28 November 2020 4,272 4 View

Can someone advise me to do Rietveld Refinement of the material whose Crystallographic Information Framework (CIF) file is not available?

10 October 2020 7,411 9 View

How to fix the refinement on Fullprof?

I have an XRD pattern of malachite phase in a range of 5-50 degree in 2 theta. After that, I use MID-JADE software to refine the pattern and it shows a good refinement with low R-value and GOF...

03 October 2020 3,613 8 View

What should be the Bragg R-factor value to stop at while performing the Rietveld Refinement?

How does the Bragg-R factor value effects the chi-square value?

22 September 2020 5,784 4 View

How is it possible to simulate or model particle morphology using X-ray powder diffraction?

Hello everyone! I suppose the XRD of sample LaPO4 has some anisotropic line broadening along [h00]. How could I model the shape of particle using WPPF method or something else? Diffraction...

21 September 2020 1,823 3 View