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shift in Kohn-Sham potential while calculating work function Date: 2022/10/05 17:16 Name: Rishabh Sharma Dear Sir, I am still learning to calculate work function using OpenMX. I am trying to calculate the work function of Al (111). Calculated value of work function is 4.42 eV at 230 K. The problem that i am facing is "shift in Kohn-Sham potential in 'a' direction". Please see the image in link below: https://ibb.co/Lt8qdLv Input file is as follows: # # File Name # System.CurrrentDirectory ./ # default=./ System.Name Al111 level.of.stdout 1 # default=1 (1-3) level.of.fileout 1 # default=1 (1-3) # # Definition of Atomic Species # Species.Number 2 <Definition.of.Atomic.Species Al Al7.0-s2p1d1 Al_PBE19 E Al7.0-s2p1d1 E Definition.of.Atomic.Species> # # Atoms # Atoms.Number 14 Atoms.SpeciesAndCoordinates.Unit Ang # Ang|AU <Atoms.SpeciesAndCoordinates 1 E 10.000000 0.000000 0.000000 0.0 0.0 2 E 23.991540 0.000000 0.000000 0.0 0.0 3 Al 12.331923 0.000000 1.648919 1.5 1.5 4 Al 14.663847 0.000000 3.297838 1.5 1.5 5 Al 16.995770 0.000000 0.000000 1.5 1.5 6 Al 19.327693 0.000000 1.648919 1.5 1.5 7 Al 21.659617 0.000000 3.297838 1.5 1.5 8 Al 12.331921 1.428005 4.122296 1.5 1.5 9 Al 14.663844 1.428005 0.824458 1.5 1.5 10 Al 16.995768 1.428005 2.473377 1.5 1.5 11 Al 19.327691 1.428005 4.122296 1.5 1.5 12 Al 21.659614 1.428005 0.824458 1.5 1.5 13 E 10.000000 1.428005 2.473377 0.0 0.0 14 E 23.991540 1.428005 2.473377 0.0 0.0 Atoms.SpeciesAndCoordinates> Atoms.UnitVectors.Unit Ang <Atoms.UnitVectors 73.991540 0.00000 0.00000 0.00000 2.85601 0.00000 0.00000 0.00000 4.94676 Atoms.UnitVectors> # # SCF or Electronic System # scf.XcType GGA-PBE # LDA|LSDA-CA|LSDA-PW scf.SpinPolarization off # On|Off|NC scf.ElectronicTemperature 230 # default=300 (K) scf.energycutoff 150 # default=150 (Ry) scf.maxIter 700 # default=40 scf.EigenvalueSolver Band # Recursion|Cluster|Band scf.Kgrid 1 4 4 # means n1 x n2 x n3 scf.Mixing.Type Rmm-Diisk # Simple|Rmm-Diis|Gr-Pulay scf.Init.Mixing.Weight 0.01 # default=0.30 scf.Min.Mixing.Weight 0.001 # default=0.001 scf.Max.Mixing.Weight 0.01 # default=0.40 scf.Mixing.History 50 # default=5 scf.Mixing.StartPulay 20 # default=6 scf.criterion 1.0e-8 # default=1.0e-6 (Hartree) ESM.switch on1 # off, on1=v|v|v, on2=m|v|m, on3=v|v|m, on4=on2+EF Thanks & Regards

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Re: shift in Kohn-Sham potential while calculating work function ( No.1 ) Date: 2022/10/20 15:13 Name: T. Ozaki Hi, I got the same work function of 4.42 eV using your input file, and the 3D isosurface of vhart.cube is found to be http://www.openmx-square.org/forum/img/Al111.JPG There seems no problem. What do you mean by "The problem that i am facing is "shift in Kohn-Sham potential in 'a' direction"." Regards, TO Re: shift in Kohn-Sham potential while calculating work function ( No.2 ) Date: 2022/11/08 21:43 Name: Rishabh Sharma Dear Sir, Thank you for the reply. By shift i mean calculated values of Kohn-Sham potential are shifted in "a" direction in unit cell. In the image link below kohn-sham potential are shifted in 'a' direction with respect to atoms in unit cell: https://ibb.co/Lt8qdLv Although, i thought about it. please correct me if i am wrong, this shift is due to "ESM.buffer.range" default value i.e. 10 Ang. I again calculated the work function by shifting my atoms in unit cell by 12 Ang in 'a' direction. With this modifications Kohn-sham potentials are not shifted but are at the same position as atoms in original unit cell as shown in the link below: https://ibb.co/Dtq4GJQ With this modifications calculated value of Work function is 4.408 eV. Thanks & Regards

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