Mr. AK These are the works i mentioned to in my initial mesg. (specially Krieger et al.) where we tried it. But it does nothing. So we removed it. Regards, S
Dear Mr. AK. Can you kindly point me to paper that you have in mind (where it is mentioned in the Hamiltonian)? Regards S
Hi Mr. Kefayati, There is no particular explicit rule for questions being posted on the Elk forum. However, my past experience shows that there are 3 types of questions: 1. very well posed and informed question containing a bug reports. This type of questions are taken up very quickly by Kay. 2. questions regarding complex Physics described or potential problem with running of the code. This type of questions are usually next. These two types of questions usually require direct developers input....
Hi Mr. Kefayati, There is no particular explicit rule for questions being posted on the Elk forum. However, my past experience shows that there are 3 types of questions: 1. very well posed and informed question containing a bug reports. This type of questions are taken up very quickly by Kay. 2. questions regarding complex Physics described or potential problem with running of the code. This type of questions are usually next. These two types of questions usually require direct developers input....
Dear Ronald, I took your elk.in and tried to run it. I am unable to reproduce your data. I get exactly the same band structure with M in x or y direction. Can you try the input file I am attaching? I also attach the BAND.OUT file. Best s
Dear Andrew, BSE uses two variable: nvbse and ncbse which you can specify in elk.in. First one is number of valence bands and second is the number of conduction bands used for BSE calculations. If nvbse was equal to all occupied and ncbse all empty states you will get the full spectrum. However, since BSE is very computationally demanding, active space is reduced and you get absorption from only restricted set of states. This also implies that you cannot just add the BSE and RPA spectra. Best Sa...
Two types of files obtained by task 320. Results obtained without LFE are written in files EPSILON-TDDFT-33.OUT. Results obtained with LFE are written to EPSM_TDDFT_33.out. In order to generate results with LFE you must set gmaxrf>1. With task 320 you can use various kernels fxctype =0 is RPA, 210 is bootstrap, 211 is single iteration bootstrap etc. Task 121 also produces optical spectra, but this is always using RPA and without LFE. These results are written to file EPSILON_33.OUT.
Dear wkq, All units in the ELK code are atomic units. 1 unit of field is = 1715.255541 Tesla. Please check page 12 of the Elk manual for this. Setting bfcm or bfieldfc breaks the symmetry and either is sufficient for ferro-magnetic materials. For AFM or non-collinear materials you would need to use bfieldcmt, where you need to point it in the direction of the moment for the corresponding atom. Best Sangeeta
You could plot the moment as a function of U. Do you ever get numbers greater than 1.7 for a larger value of U?
Hi Yilyu, I recommend you use LDA+U by applying U to the Nd. Best
Dear Mr. Wang, I looked at your elk.in. The lattice parameter is ~1.5 atomic units (i.e. ~0.8Angstrom) for a 2 atom unit-cell. I believe this is most likely a mistake and is the reason for the error message. Please note, as stated in the manual, all the inputs and outputs in the ELK code are in atomic units. I also would like to mention that ELK is a community project, in that the code is distributed by the authors under GPL and has no monetary profit for anyone involved. The team of people answering...
This is the incident fluence. You can increase by increasing the amplitude of FWHM of the pulse.
The output is written to files with names like TDOS_TS0xxxxxx.OUT. where xxxx is the time step. In order to write TD-DOS you must set tddos .true. in elk.in and ntswrite 1000 This indicates that the DOS is written each 1000th step.
You do not need to set bfieldc. Just set the bfcmt and that is it.
Dear Zhou, if you want to restart TDDFT run you use: tasks 461 and run the code. task 460 starts from t=0 and 461 starts from where ever your job ended.
Run ground state with tasks 0 ngridk 8 8 8 Then run another run with tasks 1 ngridk 76 76 76 maxscl 1
You can restart TD-DFT by using tasks 461
yes. fxctype =0 is RPA 212 is not a good Kernel. It is badly behaved. There are no other kernels. Some times single interation BS has shown to be better behaved that the fully iterative one. I would first try the default option. yes TDDFT uses wplot to plot the spectra.
Elk version: 6.2.08
Dear Minsik, I am unable to reproduce your results with your elk.in. Perhaps something is not right with your compilation/running script. With your elk.in I get the following EVALCORE. The position of the 5s state is 3.36Ha. This is ~0.3Ha less than experiemntal value. I think the rest is due to GW corrections (please see: Physical review letters 122 (21), 217202 (2019)). Best Sangeeta EVALCORE: Species : 1 (Pt), atom : 1 n = 1, l = 0, k = 1 : -2877.728632 n = 2, l = 0, k = 1 : -504.8655061 n = 2,...
Hi Myron, Within TDDFT only the occupied DOS is calculated. For more details on how it is done please see: Ultrafast laser induced local magnetization dynamics in Heusler compounds, P Elliott, T Müller, JK Dewhurst, S Sharma, EKU Gross, Scientific Reports 6, 38911 (2016). Best Sangeeta
Please look at file: EPSM_TDDFT for elements with LFE.
About what elk returns: it prints the macrioscopic response function. However all microscopic parts like LFE are included in inversion of the matrix and in the end you just look at the macroscopic part that ca be compared to the experiments.
Please see Fig. 1 of the following link for the structure of the response function. Note that each grey-lines marked square is a matrix in and G' i.e. the response fuction is a matrix of a matrix of a matrix. This also means 1 is a identity matrix. https://arxiv.org/abs/1808.00215
For diagonal part it has almost no impact. For off-diagonal, there is no other way to do it.
Hi Harry, That is a very good question. In older version of Elk we did it component wise (i am guessing i and j reffer to x,y and z, i.e. direction of perturbation and response). But in the latest version we have implemented the full form i.e. the whole matrix is inverted. Best Sangeeta
Hi Harry, fxctype=0 is RPA. In case of task 330 this would mean adding all RPA diagrams BUT including local field effects. These local fields then lead to chi0 being different from chi chi=chi0{1+v.chi0}^-1 Sangeeta
Hi Viktor, Since whole dynamics in TD-DFT is a highly non-equlib. state, chemical potential does not really mean any thing. So no there is no Fermi energy. There is no way to calculate L either. We are hoping to have Wannier implemantation soon. But we need to wait till Sept. for that. Best
Dear Os1, The list is totally serious including Pink Floyd. The most difficult parts of the Elk code were coded to the music of Pink Floyd and hence the name on the list of contributors. Best Sharma
Dear Myron, For printing TD-DOS you need to use combination of two flags: tddos .T. ntswrite 200 The first one will print partial and total-occupied -DOS and the second one tells after how many time steps these whould be written. This obviuosly slows down the code so please choose the second option carefully. For details please check the foolowing publication: Scientific Reports 6, 38911 (2016) As for TD-occupations. i.e. excited electrons are for now released in the public version of the code. However,...
Dear Myron, The TDDFT code is not ducumented at the moment. The manual is far behind our recent developments in this area. However, if you need some specific information please let me know and I will try to ducument it here on the forum fr you. Best Sangeeta
As I said in my reply before NLO (including SHG) cannot be done with BSE.
If you are looking at a materials with strong excitonic physics then yes this is...
The code is based upon Physica Scripta T109 , 128 (2004).
Hi Luca, The answer to both is no. You cannot do NLO with bootstrap or BSE. Best...
Dear TopGun, I recommend you please read the manual of the Elk code. Such simple...
Hi Rui, My student Mr. Chung-Yu Wang is implementing this at the moment. You can...
Hi The momentum matrix elements are calculated in routine genpmatk.f90. You can slightly...
Hi Alexey, The points for plotting the band structure (plot1d) are given in terms...
The formulae are analytically derived in the reciprocal space and implemented. The...
Kurt Lejaeghere et al. Reproducibility in density functional theory calculations...
Kurt Lejaeghere et al. Reproducibility in density functional theory calculations...
Kurt Lejaeghere et al. Reproducibility in density functional theory calculations...
Kurt Lejaeghere et al. Reproducibility in density functional theory calculations...
Kurt Lejaeghere et al. Reproducibility in density functional theory calculations...
Kurt Lejaeghere et al. Reproducibility in density functional theory calculations...
Kurt Lejaeghere et al. Reproducibility in density functional theory calculations...
Hi Michael, This is correct. The chemcal potential is not at 0 in this case. What...
Hi sasa, Bandstructure using RDMFT cannot be calculated. You can calculate the DOS....
Hi Pietro, You are right about m(r) and B_xc(r) being parallel at each point in space...
(a) For now there is no such option. Though I think it will be very useful. (b) Yes...
Dear Julian, Thanks for pointing various places in which manual is lacking. We will...
Hi Jerome, Just do a few calculations for elsion RPA for a few materials with a wothout...
Hi Jerome, As you know the BSE is statically screened, i.e. with the epsilon^-1 in...
No KK relation is not necessary. One can calculate whole comples response using perturbation...
NiO is not metallic in Hartree-Fock. My preliminary calculations show it to be insulator....
The calculation as it stands is fine. It takes about 100 iterations to converge....
RPA can also be done without local field effects. That is what 121 does. If you want...
task 120 calculated the matrix elements of the grad operator. It can be shown that...
Your H atoms are too close. Please try putting the second atom at 2.4 rather than...
Here is a good link. We use Chadi Cohen k-points: http://th.fhi-berlin.mpg.de/th...
If you do not want to treat all electrons at the same footing, I suggest you use...
Hi Vito, What calculations are you talking about? If you mean ground-state then the...
Hi The bug is not in the parallel version of the code. The non-linear optics formulae...
Hi Nik, First let me point out the that when you switch on spin-orbit the system...
Dear Mr. Romaka, The emphasis of the Elk code is really on the physics. It is not...
Hi Duc, Thanks for this detailed description. Is it possible you write a mail to...
Hi Duc, Aldo has moved to US and is very busy setting up a new group. So this project...
Within codes which use periodic boundary conditions, it is not possible to add a...
chgexs 1.0
Can you please post the entire elk.in file? With given file no tests can be performed...
Partial occupations are allowed. If you reduce the occupation of 1s orbital by 0.5...
Partial occupations are allowed. If you reduce the occupation of 1s orbital by 0.5...
With bootstrap kernel (fxctype=210), even with gmaxrf=0 the results include excitonic...
I am not able to reproduce your results. I get a large vaöue of gap using GGA+U....
Looks like the default value of energy grid is used. Please use dos 1000 100 1 0.0...
Try removing the corresponding local orbital from the species file and see if you...
It looks like your system is too big (memory wise) for your computers. Hence your...
The Fermi energy for a semiconductor is not defined. It can be any where in the gap....
Hi, Can you please do the first calculation with avec 8.1220397949 0.0000000000 0.0000000000...
Hi, Can you please do the first calculation with avec 8.1220397949 0.0000000000 0.0000000000...
Sorry, I do not understand. Is your c-axis 14 or 84? the avec block must look like:...
you vaccum size (104.47a.u.) is way way way too high. this is an all-electron calculation,...
Can you please try without using mixtype 3? I think it is too aggresive
There is a bug in the code. Most compilers close the files automatically. But some...
Hi Rob, gmaxrf=0 implies that no LF are included. LFE come from the matrix nature...
Hi, Kay is talking about energy as well, namely in spin degenerate case up-spin and...
Hi Rob, Here is the input file you can use to reproduce the results. As we say in...
Hi Rob, Here is the input file you can use to reproduce the results. As we say in...
Hi Vincent, Another important parameter to check is the number of empty states (nempty)....