Dear Matteo, What exactly meant is if there is a way to control the occupation matrix like the one discuss in this article http://chemistry.tcd.ie/staff/people/gww/gw_new/research/methodology/, and here http://journals.aps.org/prb/abstract/10.1103/PhysRevB.79.235125, where you can set up or define the occupation matrix. Best Wajood ________________________________ From: [email protected] [[email protected]] on behalf of Matteo Cococcioni [[email protected]] Sent: 25 March 2015 10:13 To: PWSCF Forum Subject: Re: [Pw_forum] DFT+U and starting_ns_eigenvalue(m,ispin,I)
Dear Wajood, to be precise: the starting_ns_eigenvalue flag allows you to change the eigenvalue keeping the eigenvector fixed at what it was after the first iteration (i.e., when the first non trivial occupation matrix is obtained). But I still do not understand what you want to do. What is the difference between "filling of d levels" and "eigenvalues of the occupation matrix"? What do you mean exactly for "d levels"? If you mean Kohn-Sham states yes, you can change their occupations (there is a card to do that, after you choose occupations = 'from_input" if I'm not wrong) but they are not going to be purely d states (i.e. they are not going to correspond exactly to Bloch sums of atomic d states). Maybe some will but it all depends on the electronic structure of the system. Matteo On Wed, Mar 25, 2015 at 2:53 PM, Wajood A Diery <[email protected]<mailto:[email protected]>> wrote: Dear Matteo, I dont think this is what am doing. As far as I understand, starting_ns_eigenvalue(m,ispin,I) overwrites the mth eigenvalue not the occupation matrix it self. My question was if i can define the occupation matrix that corresponds to different filling of the d levels. Best Wajood ________________________________ From: [email protected]<mailto:[email protected]> [[email protected]<mailto:[email protected]>] on behalf of Matteo Cococcioni [[email protected]<mailto:[email protected]>] Sent: 25 March 2015 09:24 To: PWSCF Forum Subject: Re: [Pw_forum] DFT+U and starting_ns_eigenvalue(m,ispin,I) Dear Wajood, isn't this what you are already doing? Matteo On Wed, Mar 25, 2015 at 11:33 AM, Wajood A Diery <[email protected]<mailto:[email protected]>> wrote: Thank you so much. One more question: is there a way in quantum espresso to control the occupation matrix where the user can define the occupation of the orbital in the occupation matrix? Best Wajood ________________________________ From: [email protected]<mailto:[email protected]> [[email protected]<mailto:[email protected]>] on behalf of Matteo Cococcioni [[email protected]<mailto:[email protected]>] Sent: 24 March 2015 13:56 To: PWSCF Forum Subject: Re: [Pw_forum] DFT+U and starting_ns_eigenvalue(m,ispin,I) Dear Wajood, it is not a problem. the eigenvalues are printed in growing order. the important thing is that you get the xz state corresponding to the 0 eigenvalue. and it seems to be the case (although it is not a pure xz and has a component on z^2) regards, Matteo On Tue, Mar 24, 2015 at 6:30 PM, Wajood A Diery <[email protected]<mailto:[email protected]>> wrote: Dear Pwscf users, I have few questions about starting_ns_eigenvalue(m,ispin,I) and the occupation matrix for DFT+U. Am trying to fix the occupation of the d orbitals in Mn in BiMnO3. I've used starting_ns_eigenvalue(m,ispin,I) to specify the following occupation: 4 electrons in dz2, dyz, dx2-y2 and dxy and zero occupation for dxz. I was expecting to get eigenvalues such as 1.000 0.000 1.000 1.000 1.000, which give the occupation of the d-orbital, but I got 0.000 1.000 1.000 1.000 1.000? i've tried different occupations of the d-orbital and I always get the same occupation or eigenvalues : 0.000 1.000 1.000 1.000 1.000? I am not sure if I miss understand the statring_ns_eigenvalue tag or there is something else that am missing? any help or suggestion will be appreciated. Wajood Mechanical Engineering Department MIT This is the part of the input file related to my Question &system ibrav = 0, celldm(1)= 18.013436 nat = 40, ntyp = 3, ecutwfc = 60, nspin = 2, starting_magnetization(2)=1, occupations='smearing', smearing='gauss', degauss=0.01 lda_plus_u=.true. lda_plus_u_kind=1 Hubbard_U(2)=8 Hubbard_J(1,2)=1.06 starting_ns_eigenvalue(1,1,2)=1.0, starting_ns_eigenvalue(2,1,2)=0.0, starting_ns_eigenvalue(3,1,2)=1.0, starting_ns_eigenvalue(4,1,2)=1.0, starting_ns_eigenvalue(5,1,2)=1.0, The output file is: LDA+U parameters: U( 2) = 8.0000 J( 2) = 1.0600 B( 2) = 0.1217 atom 9 Tr[ns(na)] (up, down, total) = 4.00000 0.19494 4.19494 spin 1 eigenvalues: 0.000 1.000 1.000 1.000 1.000 eigenvectors: 0.110 0.701 0.037 0.000 0.153 0.795 0.016 0.023 0.000 0.166 0.000 0.004 0.885 0.000 0.111 0.096 0.279 0.055 0.000 0.570 0.000 0.000 0.000 1.000 0.000 occupations: 0.890 -0.295 0.000 -0.102 0.000 -0.295 0.205 0.000 -0.276 0.000 0.000 0.000 1.000 0.000 0.000 -0.102 -0.276 0.000 0.904 0.000 0.000 0.000 0.000 0.000 1.000 spin 2 eigenvalues: 0.020 0.020 0.021 0.065 0.070 eigenvectors: 0.000 0.512 0.416 0.071 0.000 0.000 0.004 0.193 0.803 0.000 0.542 0.000 0.000 0.000 0.458 0.000 0.484 0.390 0.126 0.000 0.458 0.000 0.000 0.000 0.542 occupations: 0.023 0.010 0.000 0.005 0.000 0.010 0.056 0.000 0.014 0.000 0.000 0.000 0.043 0.000 -0.025 0.005 0.014 0.000 0.026 0.000 0.000 0.000 -0.025 0.000 0.047 atomic mag. moment = 3.805060 _______________________________________________ Pw_forum mailing list [email protected]<mailto:[email protected]> http://pwscf.org/mailman/listinfo/pw_forum _______________________________________________ Pw_forum mailing list [email protected]<mailto:[email protected]> http://pwscf.org/mailman/listinfo/pw_forum _______________________________________________ Pw_forum mailing list [email protected]<mailto:[email protected]> http://pwscf.org/mailman/listinfo/pw_forum
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