Cd Si relaxation: Difference between revisions

Latest revision as of 08:33, 14 November 2019

Overview > fcc Si > fcc Si DOS > fcc Si bandstructure > cd Si > cd Si volume relaxation > cd Si relaxation > beta-tin Si > fcc Ni > graphite TS binding energy > graphite MBD binding energy > graphite interlayer distance > List of tutorials

Task

Relaxation of the internal coordinates of a perturbed cd Si structure.

Input

POSCAR

cubic diamond
   5.5
 0.0    0.5     0.5
 0.5    0.0     0.5
 0.5    0.5     0.0
  2
Direct
 -0.125 -0.125 -0.125
  0.125  0.125  0.130

Break of symmetry in standard diamond structure: change z position from 0.125 to 0.130.

INCAR

System = diamond Si
ISTART = 0 ; ICHARG=2
ENCUT  =    240
ISMEAR = 0; SIGMA = 0.1;
NSW    =  10; IBRION =  2
ISIF   =  2
EDIFFG = -0.0001

10 relaxation steps (NSW=10).
Conjugate-gradient algorithm (IBRION=2).
Relaxation only of internal parameters (ISIF=2).

KPOINTS

k-points
 0
Monkhorst Pack
 11 11 11
 0  0  0

Calculation

Example output after 10 relaxation steps:

POSITION                                       TOTAL-FORCE (eV/Angst)
-----------------------------------------------------------------------------------
     4.81253      4.81253      4.81250        -0.000724     -0.000724     -0.000031
     0.68747      0.68747      0.68750         0.000724      0.000724      0.000031
-----------------------------------------------------------------------------------
   total drift:                                0.000000      0.000000      0.000000

Files to watch during relaxations:
- stdout (terminal): each electronic step is written to the terminal:
- OSZICAR: a copy of the terminal output.
- OUTCAR: more detailed information on every electronic and ionic step.

Other important files:
- CONTCAR: holds the structure of the last ionic step and at the end the structural result (also very important for restarting a relaxation).
- STOPCAR: stops a relaxation.

Download

diamondSirel.tgz

Overview > fcc Si > fcc Si DOS > fcc Si bandstructure > cd Si > cd Si volume relaxation > cd Si relaxation > beta-tin Si > fcc Ni > graphite TS binding energy > graphite MBD binding energy > graphite interlayer distance > List of tutorials

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@@ Line 1: / Line 1: @@
-Description: relax the internal coordinates of a perturbed cd Si structure.
+{{Template:Bulk_systems - Tutorial}}
-----
+== Task ==
-*{{TAG|INCAR}}
- System = diamond Si
- ISTART = 0 ; ICHARG=2
- ENCUT  =    240
- ISMEAR = 0; SIGMA = 0.1;
- NSW    =  5; IBRION =  2
- ISIF   =  2
-*{{TAG|KPOINTS}}
+Relaxation of the internal coordinates of a perturbed cd Si structure.
- k-points
+== Input ==
- Monkhorst Pack
-11 11
-  0  0
-*{{TAG|POSCAR}}
+=== {{TAG|POSCAR}} ===
   cubic diamond
 .5
@@ Line 28: / Line 18: @@
 .125  0.125  0.130
-== Used INCAR Tags ==
+*Break of symmetry in standard diamond structure: change z position from 0.125 to 0.130.
-{{TAG|ENCUT}}, {{TAG|IBRION}}, {{TAG|ICHARG}}, {{TAG|ISIF}}, {{TAG|ISMEAR}}, {{TAG|ISTART}}, {{TAG|NSW}}, {{TAG|SIGMA}}, {{TAG|SYSTEM}}
+=== {{TAG|INCAR}} ===
+ {{TAGBL|System}} = diamond Si
+ {{TAGBL|ISTART}} = 0 ; {{TAGBL|ICHARG}}=2
+ {{TAGBL|ENCUT}}  =    240
+ {{TAGBL|ISMEAR}} = 0; {{TAGBL|SIGMA}} = 0.1;
+ {{TAGBL|NSW}}    =  10; {{TAGBL|IBRION}} =  2
+ {{TAGBL|ISIF}}   =  2
+ {{TAGBL|EDIFFG}} = -0.0001
+*10 relaxation steps ({{TAG|NSW}}=10).
+*Conjugate-gradient algorithm ({{TAG|IBRION}}=2).
+*Relaxation only of internal parameters ({{TAG|ISIF}}=2).
+=== {{TAG|KPOINTS}} ===
+ k-points
+ Monkhorst Pack
+11 11
+  0  0
+== Calculation ==
+*Example output after 10 relaxation steps:
+ POSITION                                       TOTAL-FORCE (eV/Angst)
+ -----------------------------------------------------------------------------------
+.81253      4.81253      4.81250        -0.000724     -0.000724     -0.000031
+.68747      0.68747      0.68750         0.000724      0.000724      0.000031
+ -----------------------------------------------------------------------------------
+    total drift:                                0.000000      0.000000      0.000000
+*Files to watch during relaxations:
+**stdout (terminal): each electronic step is written to the terminal:
+**{{TAG|OSZICAR}}: a copy of the terminal output.
+**{{TAG|OUTCAR}}: more detailed information on every electronic and ionic step.
+*Other important files:
+**{{TAG|CONTCAR}}: holds the structure of the last ionic step and at the end the structural result (also very important for restarting a relaxation).
+**{{TAG|STOPCAR}}: stops a relaxation.
 == Download ==
-[http://www.vasp.at/vasp-workshop/examples/diamondSirel.tgz diamondSirel.tgz]
+[[Media:DiamondSirel.tgz| diamondSirel.tgz]]
-----
-[[VASP_example_calculations|To the list of examples]] or to the [[The_VASP_Manual|main page]]
+{{Template:Bulk_systems}}
+Back to the [[The_VASP_Manual|main page]].
 [[Category:Examples]]