ABINIT Discussion Forums

Hello Denis,


You should look at the natfix/iatfix variables for fixing atoms as well as natfixx, natfixy, natfixz and iatfixx, iatfixy and iatfixz for fixing atoms only in a given direction (or two if you wish).


David

Hello, Look at the input variable called "charge", it allows you to remove or add electrons from the system (charge 2 means your system is in charge +2, with two electrons removed). You have to be carefull about that due to periodic replicas of the charge (see for example Makov, G. & P...

Hello, I'm not sure if what you are looking for is physically relevant. If you are trying to analyze a transition path between two stable (or at least metastable) configurations of one particular atom, I would advice you to keep your cell unchanged, but maybe using a larger cell (letting the cell re...

Hello, In order to attach these file, one workaround would be to rename them as cubo2_EIG.nc.in and cubo2_GW.in. For the interpolation, are you using the EIG.nc from the second dataset of your cubo2 input file ? If not, that might be the error that you get. Indeed, you should do : python ab_extended...

Dear Mutta,


Could you please post all your input files that you used to generate the *GW and *EIG.nc file as well as these two files ? Otherwise, its difficult to tell you what's wrong ...


David

Dear Mutta,


The script you have to use is ab_extended_scissors_guess.py.

You would then do :

python ab_extended_scissors_guess.py cubo2_EIG.nc cubo2_GW (without the +)

Note that you need numpy and matplotlib installed in your python path.


David

Hello,

I dont know what your system is but in the SCF calculation, you should converge your k point grid in the 3 directions, not only along gamma-Z.

David

Hello,


Have you relaxed your system to equilibrium before doing phonon frequencies ? If not, that might explain your negative answers.


David

Hello, Your reduced coordinates are not precise enough for abinit to find the correct symetries, you should add more decimals (I think 8 is the minimum to get the symetries) = 0.3333 => 0.3333333333 0.6667 => 0.6666666667 Or you can use also : 0.3333 => 1/3 0.6667 => 2/3 This is recognized by abinit...

Hello,

You should check that udtset is not used in your input file. If this is not the case, it is difficult to say anything else without having your full input file.

David

Hello,

I guess you might ask this in the PWscf forum or mailing list ? And even there, it seems to something more related to your operating system than to PWscf ...

David

Hi Sabine, In your DFT calculation, when you produce your KSS file (dataset 2), have you checked that all the states are converged ? The negative bandgap with kssform 3 is very strange ... I would also recommend you using tolvrs as a convergence criterium for the SCF calculation (dataset 1) instead ...

Hi

I forgot to say also, I think you should use nband2 100 (the same number as nbandkss2) for your second dataset

I hope it will solve your problem

David

Hi, I would advice you these : 1. Generate your KSS file with the number of bands you want for the calculation of the screening and sigma : nbandkss 100 (I suspect that you have only 8 bands in your kss file ... but not sure, check that in your output file) 2. Use also kssform 3 3. Remove the ecutwf...

Hello,

Before reaching convergence, some steps might get into this kind of unphysical negative densities at some points. You should check that at convergence, this Warning has disappeared.

David

Hi, Usually the last bands of the calculations are more difficult to converge and you can get such noise in the band structures. By the way, does abinit tell you that you are converged for these bands ? Because I would suspect that the wavefunction residual for these bands is not fulfilling your con...

Hello,

This __in.gw__ is the _GW file you get after any GW calculation (optdriver 4). Just rename the _GW file to __in.gw__ and your BSE calculation should run.

David

Hello,


For now, you have to rename your GW file to "__in.gw__" and it should work.


David

Hello, The fact that you get twice the energy of the system with 1 atom (primitive cell) for the system with 2 atoms (non-primitive cell) is normal. The total energy (its absolute value) that you get out of your calculation is not physically meaningful as is. It will strongly depend on the pseudopot...

Yes,

If you want that the only degree of freedom of your 20th atom is the z axis, then you have to fix its x and y positions using natfixx 1 iatfixx 20 natfixy iatfixy 20

David

Hello,

You should specify the number of atoms that are fixed in each direction with the corresponding input variables natfix, natfixx, natfixy and natfixz. Otherwise the code considers that natfix variables are 0 (and does not take into account the iatfix variables)

David

Hello, Your ecut is incredibly low ... 54 eV is ... 2 Hartrees. Even for silicon, you should use an ecut of minimum 8 Hartrees, depending on the property you aim to look for. I would start by increasing the ecut to 30 Hartrees or so (you have oxygen so its at east this cutoff energy). You should the...

Hello, You forgot to attach the figure in your post. If you have convergence problems, you might try other values of iscf, for example a simple mixing (iscf = 2) with a low mixing parameter (diemix 0.3 for example). You can of course start from your wavefunction or density that you have already reac...

Hello, Well in that case you might have to "hack" a little bit the code. For example you can change the cut3d.F90 routine so that it reads in the wavefunctions (this is already done) and then writes it to a file. I guess it would not be too difficult. But what are the other quantities you ...

Hello,

If you want to have a look at the wavefunction, you can use the cut3d post-processing tool. You can for example visualize the wavefunction for a specific state. You can use cut3d for analyzing densities (_DEN), potentials (_POT), wavefunctions (_WFK), ....

I hope it helps you

David