H2O: Difference between revisions

Revision as of 09:55, 28 April 2017

Overview > O atom > O atom spinpolarized > O atom spinpolarized low symmetry > O dimer > CO > CO vibration > CO partial DOS > H2O > H2O vibration > H2O molecular dynamics > Further things to try > List of tutorials

Task

Relaxation of an Failed to parse (Conversion error. Server ("cli") reported: "[INVALID]"): {\displaystyle \mathr{H}_{2}\mathrm{O}} molecule.

Input

POSCAR

H2O _2
0.52918   ! scaling parameter
 15 0 0
 0 15 0
 0 0 15
1 2
select
cart
     0.00     0.00     0.00 F F F
     1.10    -1.43     0.00 T T F
     1.10     1.43     0.00 T T F

All coordinates are scaled by the factor 0.52918.

INCAR

PREC = Normal    ! standard precision 
ENMAX = 400      ! cutoff should be set manually
ISMEAR = 0 ; SIGMA = 0.1
IBRION = 1       ! use DIIS algorithm to converge
NFREE = 2        ! 2 independent degrees of freedom
NSW = 10         ! 10 ionic steps
EDIFFG = -0.02   ! forces smaller 0.02 A/eV

KPOINTS

Gamma-point only
 0
Monkhorst Pack
 1 1 1
 0 0 0

Calculation

Use PREC=Normal (Default for VASP.5.X)
It is strongly urged that the energy cutoffs are set manually in the INCAR file, as it provides more control over the calculations.
For the ionic optimization the DIIS algorithm is used. This algorithm builds an approximation of the Hessian matrix and converges usually faster than the conjugate gradient algorithm. It is however recommended to set the independent degrees of freedom manually. *EDIFFG determines when to terminate the relaxation. Positive values: energy change between steps must be less than the value set by EDIFFG. Negative values: $|\mathbf{F}_{i}| < |\mathrm{EDIFFG}| \forall i=1,N_{\mathrm{ions}}$ .

Download

H2O.tgz

To the list of examples or to the main page

@@ Line 42: / Line 42: @@
 *Use {{TAG|PREC}}=''Normal'' (Default for VASP.5.X)
 *It is strongly urged that the energy cutoffs are set manually in the {{TAG|INCAR}} file, as it provides more control over the calculations.
-*For the ionic optimization the DIIS algorithm is used. This algorithm builds an approximation of the Hessian matrix and converges usually faster than the conjugate gradient algorithm. It is however recommended to set the independent degrees of freedom manually. *{{TAG|EDIFFG}} determines when to terminate the relaxation. Positive values: energy change between steps must be less than the value set by {{TAG|EDIFFG}}. Negative values: <math>|\mathbf{F}_{i}| < |EDIFFG| \forall i=1,N_{\mathrm{ions}} </math>.
+*For the ionic optimization the DIIS algorithm is used. This algorithm builds an approximation of the Hessian matrix and converges usually faster than the conjugate gradient algorithm. It is however recommended to set the independent degrees of freedom manually. *{{TAG|EDIFFG}} determines when to terminate the relaxation. Positive values: energy change between steps must be less than the value set by {{TAG|EDIFFG}}. Negative values: <math>|\mathbf{F}_{i}| < |\mathrm{EDIFFG}| \forall i=1,N_{\mathrm{ions}} </math>.
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