[QE-users] N2 adsorption on Na surface
Giuseppe Mattioli
giuseppe.mattioli at ism.cnr.it
Sat Nov 9 15:54:30 CET 2024
PS. Otherwise you may change the nitrogen PP and use an US/PAW one
with a lower suggested cutoff. I've used with satisfaction the SSSP
efficiency one with a cutoff of 60/480 Ry
Best
G.
Quoting Federico Verdicchio <federico.verdicchio at unicam.it>:
> Dear all
> I am attempting to simulate the adsorption of an N₂ molecule on a Na(100)
> slab using QE. In my input file, I’m using a 12-layer Na 2x2 supercell with
> a 15 Å vacuum gap. I have kept the interlayers fixed, allowing only the top
> 3 surface layers on both ends to relax, with an N₂ molecule on each surface
> oriented perpendicular to the slab.
>
> Additionally, I am using:
>
> - The DFT-D3 van der Waals correction
> - assume_isolated=2D to truncate interactions along the z-axis
> - nspin=2 to allow for unconstrained polarization
>
> The calculation has not yet converged, but it appears to be resulting in a
> shortening of the N≡N bond, which is the opposite of what I expected.
>
> Am I missing something here?
>
> Thank you for any suggestions!
>
> Sincerely,
> Federico
>
> Input file:
> &CONTROL
> calculation = 'relax'
> etot_conv_thr = 1.0000000000d-04
> forc_conv_thr = 1.0000000000d-03
> outdir = ""
> prefix = ""
> pseudo_dir = "./SSSP_precision_pseudos"
> verbosity = 'low'
> restart_mode='from_scratch'
> /
>
> &SYSTEM
> ibrav = 0
> A = 8.30638
> nat = 52
> ntyp = 2
> ecutrho = 385 ! *11
> ecutwfc = 35
> occupations = 'smearing'
> smearing = 'gaussian'
> degauss = 0.01
> assume_isolated = '2D'
> vdw_corr = 'dft-d3'
> nspin = 2
> starting_magnetization(1)= 0 ! Na
> starting_magnetization(2)= 0.1 ! N
> /
>
> &ELECTRONS
> conv_thr = 1.0000000000d-6 ! Default
> electron_maxstep = 200
> mixing_beta = 4.0000000000d-01
> /
>
> &IONS
> ion_dynamics = 'bfgs'
> /
>
> CELL_PARAMETERS {alat}
> 1.000000000000000 0.000000000000000 0.000000000000000
> 0.000000000000000 1.000000000000000 0.000000000000000
> 0.000000000000000 0.000000000000000 4.683585508970213
> ATOMIC_SPECIES
> Na 22.98900 Na.paw.z_9.ld1.psl.v1.0.0-low.upf
> N 14.00650 N.oncvpsp.upf
> ATOMIC_POSITIONS {crystal}
> Na 0.000000000000000 0.000000000000000 -0.000032000000000 1 1 1
> Na 0.000000000000000 0.500000000000000 -0.000032000000000 1 1 1
> Na 0.500000000000000 0.000000000000000 -0.000032000000000 1 1 1
> Na 0.500000000000000 0.500000000000000 -0.000032000000000 1 1 1
> Na 0.000000000000000 0.000000000000000 0.106684000000000 1 1 1
> Na 0.000000000000000 0.500000000000000 0.106684000000000 1 1 1
> Na 0.500000000000000 0.000000000000000 0.106684000000000 1 1 1
> Na 0.500000000000000 0.500000000000000 0.106684000000000 1 1 1
> Na 0.000000000000000 0.000000000000000 0.213377000000000 0 0 0
> Na 0.000000000000000 0.500000000000000 0.213377000000000 0 0 0
> Na 0.500000000000000 0.000000000000000 0.213377000000000 0 0 0
> Na 0.500000000000000 0.500000000000000 0.213377000000000 0 0 0
> Na 0.000000000000000 0.000000000000000 0.320068000000000 0 0 0
> Na 0.000000000000000 0.500000000000000 0.320068000000000 0 0 0
> Na 0.500000000000000 0.000000000000000 0.320068000000000 0 0 0
> Na 0.500000000000000 0.500000000000000 0.320068000000000 0 0 0
> Na 0.000000000000000 0.000000000000000 0.426760000000000 0 0 0
> Na 0.000000000000000 0.500000000000000 0.426760000000000 0 0 0
> Na 0.500000000000000 0.000000000000000 0.426760000000000 0 0 0
> Na 0.500000000000000 0.500000000000000 0.426760000000000 0 0 0
> Na 0.000000000000000 0.000000000000000 0.533446000000000 1 1 1
> Na 0.000000000000000 0.500000000000000 0.533446000000000 1 1 1
> Na 0.500000000000000 0.000000000000000 0.533446000000000 1 1 1
> Na 0.500000000000000 0.500000000000000 0.533446000000000 1 1 1
> Na 0.250000000000000 0.250000000000000 0.053371000000000 1 1 1
> Na 0.250000000000000 0.750000000000000 0.053371000000000 1 1 1
> Na 0.750000000000000 0.250000000000000 0.053371000000000 1 1 1
> Na 0.750000000000000 0.750000000000000 0.053371000000000 1 1 1
> Na 0.250000000000000 0.250000000000000 0.160012000000000 0 0 0
> Na 0.250000000000000 0.750000000000000 0.160012000000000 0 0 0
> Na 0.750000000000000 0.250000000000000 0.160012000000000 0 0 0
> Na 0.750000000000000 0.750000000000000 0.160012000000000 0 0 0
> Na 0.250000000000000 0.250000000000000 0.266740000000000 0 0 0
> Na 0.250000000000000 0.750000000000000 0.266740000000000 0 0 0
> Na 0.750000000000000 0.250000000000000 0.266740000000000 0 0 0
> Na 0.750000000000000 0.750000000000000 0.266740000000000 0 0 0
> Na 0.250000000000000 0.250000000000000 0.373399000000000 0 0 0
> Na 0.250000000000000 0.750000000000000 0.373399000000000 0 0 0
> Na 0.750000000000000 0.250000000000000 0.373399000000000 0 0 0
> Na 0.750000000000000 0.750000000000000 0.373399000000000 0 0 0
> Na 0.250000000000000 0.250000000000000 0.480132000000000 1 1 1
> Na 0.250000000000000 0.750000000000000 0.480132000000000 1 1 1
> Na 0.750000000000000 0.250000000000000 0.480132000000000 1 1 1
> Na 0.750000000000000 0.750000000000000 0.480132000000000 1 1 1
> Na 0.250000000000000 0.250000000000000 0.586794000000000 1 1 1
> Na 0.250000000000000 0.750000000000000 0.586794000000000 1 1 1
> Na 0.750000000000000 0.250000000000000 0.586794000000000 1 1 1
> Na 0.750000000000000 0.750000000000000 0.586794000000000 1 1 1
> N 0.500000000000000 0.250000000000000 0.638203000000000 1 1 1
> N 0.500000000000000 0.250000000000000 0.667799000000000 1 1 1
> N 0.250000000000000 0.000000000000000 0.948559000000000 1 1 1
> N 0.250000000000000 0.000000000000000 0.918963000000000 1 1 1
> K_POINTS automatic
> 7 7 1 0 0 0
>
>
> --
> *Federico Verdicchio *
> *Ph.D. in Chemical Sciences*
> *School of Science and Technology - Chemistry Division*
> *Via S. Agostino, 1*
> *62032 Camerino (MC)*
> *Italy*
> *Phone: +39 334 2758061*
>
> --
GIUSEPPE MATTIOLI
CNR - ISTITUTO DI STRUTTURA DELLA MATERIA
Via Salaria Km 29,300 - C.P. 10
I-00015 - Monterotondo Scalo (RM)
Mob (*preferred*) +39 373 7305625
Tel + 39 06 90672342 - Fax +39 06 90672316
E-mail: <giuseppe.mattioli at ism.cnr.it>
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