Ni 100 surface relaxation: Difference between revisions

Latest revision as of 13:55, 14 November 2019

Overview > Ni 100 surface relaxation > Ni 100 surface DOS > Ni 100 surface bandstructure > Ni 111 surface relaxation > CO on Ni 111 surface > Ni 111 surface high precision > partial DOS of CO on Ni 111 surface > vibrational frequencies of CO on Ni 111 surface > STM of graphite > STM of graphene > collective jumps of a Pt adatom on fcc-Pt (001): Nudged Elastic Band Calculation > List of tutorials

Task

Relaxation of the first two layers of a Ni (100) surface.

Input

POSCAR

fcc (100) surface
 3.53
   .50000   .50000   .00000
  -.50000   .50000   .00000
   .00000   .00000  5.00000
  5
Selective Dynamics
Kartesisch
   .00000   .00000   .00000 F F F
   .00000   .50000   .50000 F F F
   .00000   .00000  1.00000 F F F
   .00000   .50000  1.50000 T T T
   .00000   .00000  2.00000 T T T

Ni lattice constant of 3.53 $\AA$ .
1 atom per layer: p(1x1) cell.
5 nickel layers.
First two layers (of one side) relaxed.
$3\times3.53 = 10.59 \AA$ vacuum.

INCAR

  ISTART = 0; ICHARG = 2
    
general:
  SYSTEM = clean Ni(100) surface
  ENCUT = 270 
  ISMEAR = 2 ; SIGMA = 0.2
  ALGO = Fast
  EDIFF = 1E-6
    
spin:
  ISPIN=2
  MAGMOM = 5*1
    
dynamic:
  NSW = 100
  POTIM = 0.8
  IBRION = 1

Initial charge-density in startjob from overlapping atoms.
Default energy cut-off of 270 eV.
MP-smearing (metal).
Spin-polarized calculation with initial moment of 1.
Ionic relaxation used.

KPOINTS

k-points
0
Monkhorst-Pack
9 9 1
0 0 0

Equally spaced mesh.
Odd mesh, centered on $\Gamma$ .
15 k points in irreducible Brillouin zone (IBZ).
Only one k point in z-direction for surface.

Calculation

The sample output for the forces in the OUTCAR file should look like this (first and last step):

First step:

POSITION                                       TOTAL-FORCE  (eV/Angst)
-----------------------------------------------------------------------------------
     0.00000      0.00000      0.00000         0.000000      0.000000      0.391352
     0.00000      1.76500      1.76500         0.000000      0.000000     -0.397024
     0.00000      0.00000      3.53000         0.000000      0.000000      0.005117
     0.00000      1.76500      5.29500         0.000000      0.000000      0.391161
     0.00000      0.00000      7.06000         0.000000      0.000000     -0.390607
-----------------------------------------------------------------------------------
   total drift:                                0.000000      0.000000      0.016391

Last step:

POSITION                                       TOTAL-FORCE  (eV/Angst)
-----------------------------------------------------------------------------------
     0.00000      0.00000      0.00000         0.000000      0.000000      0.399012
     0.00000      1.76500      1.76500         0.000000      0.000000     -0.377003
     0.00000      0.00000      3.53000         0.000000      0.000000      0.105799
     0.00000      1.76500      5.32685         0.000000      0.000000     -0.062054
     0.00000      0.00000      7.02377         0.000000      0.000000     -0.065753
-----------------------------------------------------------------------------------
   total drift:                                0.000000      0.000000     -0.042925

Energy changes during relaxation from -25.556 to -25.571 eV which gives a relaxation energy of $E^{\mathrm{rel}} = -15$ meV. Use p4vasp to check the convergence:

The surface energy of 0.86 eV for the unrelaxed surface is calculated in the following:

$\sigma^{\mathrm{unrel}} = \frac{1}{2} (E_{\mathrm{surf}}-N_{\mathrm{atoms}} \cdot E_{\mathrm{bulk}}) = \frac{1}{2} (-25.556-5\cdot(-5.457))= 0.86$ eV.

The surface energy of 0.84 eV for the relaxed surface is then calculated as:

$\sigma = \sigma^{\mathrm{unrel}} + E^{\mathrm{rel}} = 0.84$ eV.

The final geometry (from the CONTCAR or OUTCAR file) should look as follows:

fcc (100) surface
   3.53000000000000
     0.5000000000000000      0.5000000000000000      0.000000000000000
    -0.5000000000000000      0.5000000000000000      0.000000000000000
     0.0000000000000000      0.0000000000000000      5.000000000000000
   Ni
     5
Selective Dynamics
Direct
0.0000000000000000   0.0000000000000000   0.0000000000000000 F F F
0.0000000000000000   0.5000000000000000   0.1000000000000014 F F F
0.0000000000000000   0.0000000000000000   0.2000000000000028 F F F
0.5000000000000000   0.5000000000000000   0.3018043743226639 T T T
0.0000000000000000   0.0000000000000000   0.3979474020596729 T T T

Inward relaxation of surface layers:
- $\Delta d_{12}$ = ((0.3979-0.3018)-0.1)/0.1*100=-3.9%.
- $\Delta d_{12}$ = ((0.3018-0.2000)-0.1)/0.1*100=+1.8%.

Use p4vasp to visualize the relaxation:

Download

Ni100clean_rel.tgz

Overview > Ni 100 surface relaxation > Ni 100 surface DOS > Ni 100 surface bandstructure > Ni 111 surface relaxation > CO on Ni 111 surface > Ni 111 surface high precision > partial DOS of CO on Ni 111 surface > vibrational frequencies of CO on Ni 111 surface > STM of graphite > STM of graphene > collective jumps of a Pt adatom on fcc-Pt (001): Nudged Elastic Band Calculation > List of tutorials

@@ Line 1: / Line 1: @@
-Description: relax the first two layers of a Ni (100) surface.
+{{Sur_sci - Tutorial}}
-----
+== Task ==
-*INCAR
-<pre>
-   ISTART = 0; ICHARG = 2
- general:
+Relaxation of the first two layers of a Ni (100) surface.
-   SYSTEM = clean Ni(100) surface
-   ENCUT  = 270
-   ISMEAR =    2  ; SIGMA = 0.2
-   ALGO= Fast
- spin:
+== Input ==
-   ISPIN=2
-   MAGMOM = 5*1
- dynamic:
-   NSW   = 100
-   POTIM = 0.2
-   IBRION = 1
-</pre>
-*KPOINTS
+=== {{TAG|POSCAR}} ===
-<pre>
-k-points
-Monkhorst-Pack
-9 1
-0 0
-</pre>
-*POSCAR
 <pre>
 fcc (100) surface
@@ Line 47: / Line 23: @@
     .00000   .00000  2.00000 T T T
 </pre>
+*Ni lattice constant of 3.53<math>\AA</math>.
+*1 atom per layer: p(1x1) cell.
+*5 nickel layers.
+*First two layers (of one side) relaxed.
+*<math>3\times3.53 = 10.59 \AA</math> vacuum.
+=== {{TAG|INCAR}} ===
+   {{TAGBL|ISTART}} = 0; {{TAGBL|ICHARG}} = 2
+ general:
+   {{TAGBL|SYSTEM}} = clean Ni(100) surface
+   {{TAGBL|ENCUT}} = 270
+   {{TAGBL|ISMEAR}} = 2 ; {{TAGBL|SIGMA}} = 0.2
+   {{TAGBL|ALGO}} = Fast
+   {{TAGBL|EDIFF}} = 1E-6
+ spin:
+   {{TAGBL|ISPIN}}=2
+   {{TAGBL|MAGMOM}} = 5*1
+ dynamic:
+   {{TAGBL|NSW}} = 100
+   {{TAGBL|POTIM}} = 0.8
+   {{TAGBL|IBRION}} = 1
+*Initial charge-density in startjob from overlapping atoms.
+*Default energy cut-off of 270 eV.
+*MP-smearing (metal).
+*Spin-polarized calculation with initial moment of 1.
+*Ionic relaxation used.
+=== {{TAG|KPOINTS}} ===
+<pre>
+k-points
+Monkhorst-Pack
+9 1
+0 0
+</pre>
+*Equally spaced mesh.
+*Odd mesh, centered on <math>\Gamma</math>.
+*15 k points in irreducible Brillouin zone (IBZ).
+*Only one k point in z-direction for surface.
+== Calculation ==
+*The sample output for the forces in the {{TAG|OUTCAR}} file should look like this (first and last step):
+First step:
+ POSITION                                       TOTAL-FORCE  (eV/Angst)
+ -----------------------------------------------------------------------------------
+.00000      0.00000      0.00000         0.000000      0.000000      0.391352
+.00000      1.76500      1.76500         0.000000      0.000000     -0.397024
+.00000      0.00000      3.53000         0.000000      0.000000      0.005117
+.00000      1.76500      5.29500         0.000000      0.000000      0.391161
+.00000      0.00000      7.06000         0.000000      0.000000     -0.390607
+ -----------------------------------------------------------------------------------
+    total drift:                                0.000000      0.000000      0.016391
+Last step:
+ POSITION                                       TOTAL-FORCE  (eV/Angst)
+ -----------------------------------------------------------------------------------
+.00000      0.00000      0.00000         0.000000      0.000000      0.399012
+.00000      1.76500      1.76500         0.000000      0.000000     -0.377003
+.00000      0.00000      3.53000         0.000000      0.000000      0.105799
+.00000      1.76500      5.32685         0.000000      0.000000     -0.062054
+.00000      0.00000      7.02377         0.000000      0.000000     -0.065753
+ -----------------------------------------------------------------------------------
+    total drift:                                0.000000      0.000000     -0.042925
+*Energy changes during relaxation from -25.556 to -25.571 eV which gives a relaxation energy of <math>E^{\mathrm{rel}} = -15</math> meV. Use p4vasp to check the convergence:
+[[File:Fig Ni 100 surfrel 1.png|600px]]
+*The surface energy of 0.86 eV for the unrelaxed surface is calculated in the following:
+<math>\sigma^{\mathrm{unrel}} = \frac{1}{2} (E_{\mathrm{surf}}-N_{\mathrm{atoms}} \cdot E_{\mathrm{bulk}}) = \frac{1}{2} (-25.556-5\cdot(-5.457))= 0.86</math> eV.
+*The surface energy of 0.84 eV for the relaxed surface is then calculated as:
+<math> \sigma = \sigma^{\mathrm{unrel}} + E^{\mathrm{rel}} = 0.84</math> eV.
+*The final geometry (from the {{TAG|CONTCAR}} or {{TAG|OUTCAR}} file) should look as follows:
+ fcc (100) surface
+.53000000000000
+.5000000000000000      0.5000000000000000      0.000000000000000
+     -0.5000000000000000      0.5000000000000000      0.000000000000000
+.0000000000000000      0.0000000000000000      5.000000000000000
+    Ni
+ Selective Dynamics
+ Direct
+.0000000000000000   0.0000000000000000   0.0000000000000000 F F F
+.0000000000000000   0.5000000000000000   0.1000000000000014 F F F
+.0000000000000000   0.0000000000000000   0.2000000000000028 F F F
+.5000000000000000   0.5000000000000000   0.3018043743226639 T T T
+.0000000000000000   0.0000000000000000   0.3979474020596729 T T T
+*Inward relaxation of surface layers:
+** <math>\Delta d_{12}</math> = ((0.3979-0.3018)-0.1)/0.1*100=-3.9%.
+** <math>\Delta d_{12}</math> = ((0.3018-0.2000)-0.1)/0.1*100=+1.8%.
+*Use p4vasp to visualize the relaxation:
+[[File:Fig Ni 100 surfrel 2.png|800px]]
 == Download ==
-[http://www.vasp.at/vasp-workshop/examples/Ni100clean_rel.tgz Ni100clean_rel.tgz]
+[[Media:Ni100clean_rel.tgz| Ni100clean_rel.tgz]]
-----
+{{Sur_sci}}
-[[VASP_example_calculations|To the list of examples]] or to the [[The_VASP_Manual|main page]]
 [[Category:Examples]]