Dear Iurii, Thanks for clarification.
Kind regards, Dorde On Oct 11, 2023 10:14 AM, Iurii Timrov via users <[email protected]> wrote: Dear Dorde, The electronic configuration of Lu is [Xe<https://en.wikipedia.org/wiki/Xenon>] 4f14 5d1 6s2 You are using QE v6.8 with the old Hubbard input syntax. The Hubbard manifold is hard-coded in this version and it is 4f for Lu (hubbard_l = 3). So you are trying to compute U for the 4f shell which is fully occupied. The HP code is based on linear-response theory (DFPT to 1st order) which can be used for open shells only. If you try to use it for closed shells (like you do), the U parameter will diverge in the self-consistent cycle. This is indeed what you observe. Please have a look at this paper: K. Yu and E.A. Carter, J. Chem. Phys. 140, 121105 (2014). HTH Iurii -- Dr. Iurii TIMROV Senior Research Scientist Theory and Simulation of Materials (THEOS) Swiss Federal Institute of Technology Lausanne (EPFL) CH-1015 Lausanne, Switzerland +41 21 69 34 881 http://people.epfl.ch/265334 ________________________________ From: users <[email protected]> on behalf of Dorde DANGIC <[email protected]> Sent: Wednesday, October 11, 2023 9:57:58 AM To: [email protected] Subject: [QE-users] Self-consistent calculation of Hubbard U parameter diverges Dear all, I have tried to calculate the Hubbard U parameter self-consistently using hp.x code distributed with quantum-espresso software. In my calculations, the estimate of the U parameter constantly increases with each iteration. I started with a value of 0.0001 in the 0th iteration, relaxed the structure, and ran scf calculation followed by hp.x calculation. The first estimate of the U parameter is 25.6456 eV. I ran the second iteration with this value (relaxed the structure and ran scf.x/hp.x) and got the second estimate of 116.1282 eV. On the third iteration, U was 1073.3687 eV. I tried calculations with 'ortho-atomic' and 'atomic' projections. I tried calculations with the different starting U. I always get the divergence of the U parameter. I am using v.6.8 version of quantum-espresso. I attached pw.in and hp.in. Am I doing something wrong? If not, what could be the reason for this behavior? pw.in: &control prefix = 'LuH' calculation = "scf" tprnfor = .true. tstress = .true. outdir='./' pseudo_dir='/scratch/djordjedangic/LuNH/' &end &system ibrav = 0 nat = 4 ntyp = 2 ecutwfc = 100.0 occupations = 'smearing' smearing = 'gaussian' degauss = 0.015 input_dft = 'pbe' lda_plus_u = .true. lda_plus_u_kind = 0 U_projection_type = 'ortho-atomic' Hubbard_U(1) = 0.0001 &end &electrons conv_thr = 1e-14 &end ATOMIC_SPECIES Lu 174.9668 Lu.upf H 1.00784 H.upf K_POINTS automatic 12 12 12 0 0 0 CELL_PARAMETERS (angstrom) -2.494212191 -0.000000000 2.494212191 0.000000000 2.494212191 2.494212191 -2.494212191 2.494212191 -0.000000000 ATOMIC_POSITIONS (crystal) Lu -0.0000000000 0.0000000000 -0.0000000000 H 0.2500000000 0.2500000000 0.2500000000 H 0.7500000000 0.7500000000 0.7500000000 H 0.5000000000 0.5000000000 0.5000000000 hp.in: &inputhp prefix = 'LuH' outdir='./' nq1=6 nq2=6 nq3=6 conv_thr_chi=1.0d-12 / Kind regards, Dorde
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