H2O vibration: Difference between revisions

Revision as of 11:15, 6 June 2012

INCAR

SYSTEM = H2O vibration
ISMEAR = 0    # Gaussian smearing
IBRION = 6    # finite differences with symmetry
NFREE = 2     # central differences (default)
POTIM = 0.015 # default as well
EDIFF = 1E-6 
NSW = 1       # ionic steps > 0

KPOINTS

Gamma-point only
 1        ! one k-point
rec       ! in units of the reciprocal lattice vector
 0 0 0 1  ! 3 coordinates and weight

POSCAR

H2O _2                                                                          
 0.5291800
  15.0000000   0.0000000   0.0000000
   0.0000000  15.0000000   0.0000000
   0.0000000   0.0000000  15.0000000
    1    2
cart
   0.0000000   0.0000000   0.0000000
   1.1269567  13.5477107   0.0000000
   1.1269567   1.4522893   0.0000000

How many zero frequency modes are observed and why? Are the results sensitive to the step width POTIM Also try to use the linear response code (IBRION=8).

Download

1_8_H2Ovib.tgz

To the list of examples or to the main page

@@ Line 26: / Line 26: @@
 .1269567   1.4522893   0.0000000
-How many zero frequency modes are observed and why. Also try
+How many zero frequency modes are observed and why?
-to use the linear response code (IBRION=8)
+Are the results sensitive to the step width {{TAG|POTIM}}
+Also try to use the linear response code ({{TAG|IBRION}}=8).
 == Download ==
 [http://www.vasp.at/vasp-workshop/examples/1_8_H2Ovib.tgz 1_8_H2Ovib.tgz]