IWAVPR: Difference between revisions

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\noindent
\noindent
{\tt IWAVPR} determines how orbitals and/or charge density
{{TAG|IWAVPR}} determines how orbitals and/or charge density
are extrapolated from one ionic configuration to the next configuration.
are extrapolated from one ionic configuration to the next configuration.
Usually the file TMPCAR \index{FILES!T!TMPCAR|textit} is used to store
Usually the file {{TAG|TMPCAR}} is used to store old orbitals, which
old orbitals, which
are required for the prediction.If {{TAG|IWAVPR}} is larger than 10, the prediction is
are required for the prediction.
done without an external file {{TAG|TMPCAR}} (i.e. all required arrays
If {\tt IWAVPR} is larger than 10, the prediction is
are stored in the main memory, this option works from version VASP.4.1).
done without an external file TMPCAR (i.e. all required arrays
If {{TAG|IWAVPR}} is set to 10, the reader will set it to the
are stored in main memory, this option works from version VASP.4.1).
If the {\tt IWAVPR} is set to 10, the reader will set it to the
following default values:
following default values:


\begin{tabular} {ll}
*{{TAG|IWAVPR}}=12 if {{TAG|IBRION}}=0 (MD)  
{\tt IWAVPRE}=12 & if {\tt IBRION}=0 (MD) \\
*{{TAG|IWAVPR}}=11 if {{TAG|IBRION}}=1,2 (relaxation)  
{\tt IWAVPRE}=11 & if {\tt IBRION}=1,2 (relaxation) \\
\end{tabular}
\vspace{5mm}


\begin{itemize}
The following options are available for {{TAG|IWAVPR}}:
\item[0]
*{{TAG|IWAVPR}}=0 no extrapolation, usually less preferable if you want to do an
no extrapolation, usually less preferable if you want to do an
ab initio MD or a relaxation of the ions into the instantaneous groundstate.
ab initio MD or a relaxation of the ions into the instantaneous groundstate.
\item[1,11]
*{{TAG|IWAVPR}}=1|11 Simple extrapolation of the charge density using atomic charge densities is done
Simple extrapolation of the charge density using atomic charge densities is done
(eq. (9.8) in thesis G. Kresse). This switch is convenient for all kind of geometry optimizations (ionic relaxation
(eq. (9.8) in thesis G. Kresse).
This switch is convenient for all kind of geometry optimizations (ionic relaxation
and volume/cell shape with conjugate gradient or Quasi-Newton methods,
and volume/cell shape with conjugate gradient or Quasi-Newton methods,
i.e. {\tt IBRION}=1,2) \index{INCAR!I!IBRION|textit}
i.e. {{TAG|IBRION}}=1,2)  
\item[2,12]
*{{TAG|IWAVPR}}=2|12 A second order extrapolation for the orbitals and
A second order extrapolation for the orbitals and
the charge density is done (eq. (9.9) in thesis G. Kresse).A must for ab-initio  MD-runs.
the charge density is done (eq. (9.9) in thesis G. Kresse).
*{{TAG|IWAVPR}}=3|13 In this case a second order extrapolation for the orbitals, and
A must for ab-initio  MD-runs.
\item[3,13]
In this case a second order extrapolation for the orbitals, and
a  simple  extrapolation of the charge density using atomic charge densities is done.
a  simple  extrapolation of the charge density using atomic charge densities is done.
This is obviously a mixture between {\tt IWAVPR}=1 and 2, however, it is usually worse
This is obviously a mixture between *{{TAG|IWAVPR}}=1 and 2, however, it is usually worse
than {\tt IWAVPR}=2.
than *{{TAG|IWAVPR}}=2.


{\em Mind:} We don't  encourage this  setting.
Mind: We don't  encourage this  setting.
 
== Related Tags and Sections ==
{{TAG|IBRION}},
{{TAG|AGGAC}},
{{TAG|ALDAC}},
----
[[The_VASP_Manual|Contents]]
 
[[Category:INCAR]]

Revision as of 10:43, 16 January 2017

IWAVPR = 0 | 1 | 2 | 3 | 10 | 11 | 12 | 13 

Default: IWAVPR = 2 if IBRION=0 (MD) and 1,2 (relaxation)
= 0 else (static calculation)

{\tt IWAVPR}= {\tt 0 | 1 | 2 | 3 | 10 | 11 | 12 | 13}

\begin{tabular} {rl} Default: \\ {\tt IWAVPR}=2 & if {\tt IBRION}=0 (MD) and 1,2 (relaxation) \\

           =0 & else (static calculation) \\

\end{tabular} \vspace{5mm}

\noindent IWAVPR determines how orbitals and/or charge density are extrapolated from one ionic configuration to the next configuration. Usually the file TMPCAR is used to store old orbitals, which are required for the prediction.If IWAVPR is larger than 10, the prediction is done without an external file TMPCAR (i.e. all required arrays are stored in the main memory, this option works from version VASP.4.1). If IWAVPR is set to 10, the reader will set it to the following default values:

The following options are available for IWAVPR:

  • IWAVPR=0 no extrapolation, usually less preferable if you want to do an

ab initio MD or a relaxation of the ions into the instantaneous groundstate.

  • IWAVPR=1|11 Simple extrapolation of the charge density using atomic charge densities is done

(eq. (9.8) in thesis G. Kresse). This switch is convenient for all kind of geometry optimizations (ionic relaxation and volume/cell shape with conjugate gradient or Quasi-Newton methods, i.e. IBRION=1,2)

  • IWAVPR=2|12 A second order extrapolation for the orbitals and

the charge density is done (eq. (9.9) in thesis G. Kresse).A must for ab-initio MD-runs.

  • IWAVPR=3|13 In this case a second order extrapolation for the orbitals, and

a simple extrapolation of the charge density using atomic charge densities is done. This is obviously a mixture between *IWAVPR=1 and 2, however, it is usually worse than *IWAVPR=2.

Mind: We don't encourage this setting.

Related Tags and Sections

IBRION, AGGAC, ALDAC,


Contents