Cd Si relaxation: Difference between revisions

Revision as of 07:19, 9 May 2017

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

Download

diamondSirel.tgz

To the list of examples or to the main page

@@ Line 25: / Line 25: @@
   {{TAGBL|ENCUT}}  =    240
   {{TAGBL|ISMEAR}} = 0; {{TAGBL|SIGMA}} = 0.1;
-  {{TAGBL|NSW}}    =  5; {{TAGBL|IBRION}} =  2
+  {{TAGBL|NSW}}    =  10; {{TAGBL|IBRION}} =  2
   {{TAGBL|ISIF}}   =  2
+ {{TAGBL|EDIFFG}} = -0.0001
-*5 relaxation steps ({{TAG|NSW}}=5).
+*10 relaxation steps ({{TAG|NSW}}=10).
 *Conjugate-gradient algorithm ({{TAG|IBRION}}=2).
 *Relaxation only of internal parameters ({{TAG|ISIF}}=2).
@@ Line 40: / Line 41: @@
 == 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
 == Download ==