IWAVPR: Difference between revisions

Latest revision as of 09:51, 19 April 2024

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

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

Description: IWAVPR determines how orbitals and/or charge densities 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:

IWAVPR=12 if IBRION=0 (MD)
IWAVPR=11 if IBRION=1,2 (relaxation)

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). This results in superior performance 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 a mixture between IWAVPR=1 and 2, however, it is usually worse than IWAVPR=2.

Mind: We don't encourage this setting.

@@ Line 2: / Line 2: @@
 {{DEF|IWAVPR|2|if {{TAG|IBRION}}{{=}}0 (MD) and 1,2 (relaxation)|0|else (static calculation)}}
-{\tt IWAVPR}= {\tt 0 | 1 | 2 | 3 | 10 | 11 | 12 | 13}
+Description: {{TAG|IWAVPR}} determines how orbitals and/or charge densities
+are extrapolated from one ionic configuration to the next configuration.
-\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
+Usually the file {{TAG|TMPCAR}} is used to store old orbitals, which
-{\tt IWAVPR} determines how orbitals and/or charge density
+are required for the prediction.If {{TAG|IWAVPR}} is larger than 10, the prediction is
-are extrapolated from one ionic configuration to the next configuration.
+done without an external file {{TAG|TMPCAR}} (i.e. all required arrays
-Usually the file TMPCAR \index{FILES!T!TMPCAR|textit} is used to store
+are stored in the main memory, this option works from version VASP.4.1).
-old orbitals, which
+If {{TAG|IWAVPR}} is set to 10, the reader will set it to the
-are required for the prediction.
-If {\tt IWAVPR} is larger than 10, the prediction is
-done without an external file TMPCAR (i.e. all required arrays
-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:
-\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}
+The following options are available for {{TAG|IWAVPR}}:
-\vspace{5mm}
+*{{TAG|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.
+*{{TAG|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. {{TAG|IBRION}}=1,2)
+*{{TAG|IWAVPR}}=2|12 A second order extrapolation for the orbitals and the charge density is done (eq. (9.9) in thesis G. Kresse). This results in superior performance for ab-initio  MD-runs.
+<!--However, the following warning may occur: <code>Information: wavefunction orthogonal band xxx..</code>. This is a sign of band crossing and -->
+*{{TAG|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 a mixture between {{TAG|IWAVPR}}=1 and 2, however, it is usually worse than {{TAG|IWAVPR}}=2.
+:Mind: We don't  encourage this  setting.
+== Related tags and articles ==
+{{TAG|IBRION}}
-\begin{itemize}
+{{sc|IWAVPR|Examples|Examples that use this tag}}
-\item[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.
-\item[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. {\tt IBRION}=1,2) \index{INCAR!I!IBRION|textit}
-\item[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.
-\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.
-This is obviously a mixture between {\tt IWAVPR}=1 and 2, however, it is usually worse
-than {\tt IWAVPR}=2.
-{\em Mind:} We don't  encourage this  setting.
+[[Category:INCAR tag]][[Category:Ionic minimization]][[Category:Molecular dynamics]]