IWAVPR: Difference between revisions
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{ | {{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 | 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 { | 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 | |||
If | |||
following default values: | following default values: | ||
*{{TAG|IWAVPR}}=12 if {{TAG|IBRION}}=0 (MD) | |||
*{{TAG|IWAVPR}}=11 if {{TAG|IBRION}}=1,2 (relaxation) | |||
{ | |||
The following options are available for {{TAG|IWAVPR}}: | |||
*{{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. | ||
*{{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. { | i.e. {{TAG|IBRION}}=1,2) | ||
*{{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. | |||
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 { | This is obviously a mixture between *{{TAG|IWAVPR}}=1 and 2, however, it is usually worse | ||
than { | than *{{TAG|IWAVPR}}=2. | ||
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.