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
_______________________________________________ The Quantum ESPRESSO community stands by the Ukrainian people and expresses its concerns about the devastating effects that the Russian military offensive has on their country and on the free and peaceful scientific, cultural, and economic cooperation amongst peoples _______________________________________________ Quantum ESPRESSO is supported by MaX (www.max-centre.eu) users mailing list [email protected] https://lists.quantum-espresso.org/mailman/listinfo/users
