- Видео 5
- Просмотров 21 162
Vitaliy Romaka
Добавлен 25 мар 2011
Tutorials for DFT calculations, Rietveld refinement, and crystal chemistry analysis.
Elk Tutorial - Exercise 4
Exercise 4 of the Elk Tutorial covers automatic optimization of the lattice parameters with Elk package (elk.sourceforge.net).
All exercises, supplementary materials, and video guides of the Elk Tutorial are available at sites.google.com/site/tinykpoint/elk-tutorial
All exercises, supplementary materials, and video guides of the Elk Tutorial are available at sites.google.com/site/tinykpoint/elk-tutorial
Просмотров: 668
Видео
Elk Tutorial - Exercise 3
Просмотров 1,2 тыс.8 лет назад
Exercise 3 of the Elk Tutorial covers calculation, visualization, and analysis of the charge density and electron localization function with Elk package (elk.sourceforge.net). All exercises, supplementary materials, and video guides of the Elk Tutorial are available at sites.google.com/site/tinykpoint/elk-tutorial
Elk Tutorial - Exercise 2
Просмотров 1,3 тыс.9 лет назад
Exercise 2 of the Elk Tutorial covers calculation and analysis of DOS for Ge and Pb with Elk package (elk.sourceforge.net). All exercises, supplementary materials, and video guides of the Elk Tutorial are available at sites.google.com/site/tinykpoint/elk-tutorial
Elk Tutorial - Exercise 1
Просмотров 3,4 тыс.9 лет назад
Exercise 1 of the Elk Tutorial covers preparation of the elk.in file for ground state energy calculations of white and gray Sn with Elk package (elk.sourceforge.net). All exercises, supplementary materials, and video guides of the Elk Tutorial are available at sites.google.com/site/tinykpoint/elk-tutorial
VESTA example for Elk
Просмотров 15 тыс.9 лет назад
Step-by-step tutorial on how to visualize volumetric data (RHO3D.OUT, ELF3D.OUT) generated by Elk package (elk.sourceforge.net) in VESTA program (jp-minerals.org/vesta/). Don't hesitate to contact me in the case of further questions. Best wishes and have a nice plots!
2023-07-27: The link to your exercises, supplementary materials, and video guides doesn't work anymore. Is there another one? :(
Great Elk tutorial videos. Can you make similar ones for magnetism and phonon computation with Elk? highly appreciated
How to mark the scale values of the color scale?
manually in CorelDraw, Libreoffice Draw, etc.
@@vromaka thank you. I try to do/check. But how do we know which color is marked at which value?
@@kkm5384 In VESTA --> Properties-->Sections there you can view/set both limits for the scale
@@vromaka Thank a lot. :)
@@vromaka Are you referring to the "Saturation levels"? Thank you! :)
I use VASP. Can i use the output from there to generate such contour maps in 3D for charge density?
As far as I remember, there is an option to visualize VASP output in VESTA, have a look on the supported file types and programs
@@vromaka thank you. yes i can visualise and get the volumetric data. but i cannot get a similar bird's eye view projections as you got @6:26 . i get only a flat 2D surface even in bird'd eye view option. also, what is the color scale indicates? there are no values written on scale. what is the meaning of the 3D projections, dips shown in @6:26 onwards?
Thanks for the video, it very helpful! I have a question however. Whats the 2nd line you added in the *led file? (the numbers 6 6 6) Are they the number of unit cell along the x,y and z directions? Also, what if your unit cell is not orthogonal? Is there any problem in this case?
Yes, lattice parameters. The geometry in the led file doesn't really matter (but we need some fake numbers to meet the requirements of the led file format), as you will import the correct one from the GEOMETRY.OUT file
Thank you
is this necessary to copy the geometry.out text to elk.in? are they really same ?
Man at-least add some Yoga music in background if you are shy to speak
no sound in this video
Yes, I know. But I don't have some good microphone in order to record something. :)
Muchas gracias :)
hi! thanks for this tutorial but in my software the option style>properties>isosurfaces is not avaiable and i would like to do the samething as you did in your structure! please help me! thanks
This option is available only AFTER you open volumetric data (*.led file)
Great video, very helpful. Could I ask a simple question? Why the energy value in TOTENERGY.OUT is -12358 ? According to the manual, the energy unit is Hartree = 27.2eV. If so, the energy will be -12358*27.2 eV? Why is value so large for a simple system? Am I wrong in unit conversion?
+Fei Xue I';m glad to hear that. In general the energy depends on the number of electrons that atom has and the number of atoms in the unit cell. The "lighter" is the element the smaller is the energy. The energy unit conversion is rather simple. 1Ha = 2Ry (Rydberg), 1Ry = 13.606 eV, so 1Ha = 2*13.606eV = 27.212 eV. And Yes, you are completely right with your conversion. You may try to calculate Si, Ge, and Sn to see the general trend. Also you may try to calculate Zr (40) and Hf (72) and realize that the energy of Hf is about 4 times higher.
Thanks for your reply. Vitaliy. I've used VASP to calculate the energy of one Al atom in a big unit cell it's- 0.005ev, alomost 0. In reality, the energy of one single atom should be zero I guess. But when i did the same case in ELK, the energy is -241.7 Hartree. Do you know why it is so different? Thanks in advance.
+Fei Xue Well, the VASP is a pseudopotential code (only valence electrons matter), while ELK is an all-electron full-potential. The energy of an one single atom is not "0", otherwise the enthalpy of formation of materials/compounds would be just like a nuclear explosion ;)
+Vitaliy Romaka Thank you for your clarification. Then if I want to compare the energy from vasp and elk. I should compare the energy difference of two values instead of the absolute value. Am I right ?
Fei Xue No, it is not a correct comparison.