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Difference between revisions of "LSCALU"

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In many cases, the scaLAPACK LU decomposition based is ''slower'' than the serial LU decomposition (compare the timing <tt>ORTHCH</tt> in the respective {{FILE|OUTCAR}} files). Hence the default is {{TAG|LSCALU}}=.FALSE.
 
In many cases, the scaLAPACK LU decomposition based is ''slower'' than the serial LU decomposition (compare the timing <tt>ORTHCH</tt> in the respective {{FILE|OUTCAR}} files). Hence the default is {{TAG|LSCALU}}=.FALSE.
(subspace rotations are still done using scaLAPACK, however).
+
(subspace rotations, however, are still done using scaLAPACK).
  
 
== Related Tags and Sections ==
 
== Related Tags and Sections ==

Revision as of 16:20, 5 April 2014

LSCALU = [logical]
Default: LSCALU = .FALSE. 

Description: LSCALU switches on the parallel LU decomposition (using scaLAPACK) in the orthonormalization of the wave functions.


For LSCALU=.TRUE. the LU decomposition in the orthormalization of the wave functions is done in parallel, using scaLAPACK routines. Provided, of course, LSCALAPACK=.TRUE. and VASP was compiled with scaLAPACK support (precompiler flag: -DscaLAPACK).

In many cases, the scaLAPACK LU decomposition based is slower than the serial LU decomposition (compare the timing ORTHCH in the respective OUTCAR files). Hence the default is LSCALU=.FALSE. (subspace rotations, however, are still done using scaLAPACK).

Related Tags and Sections

NPAR, NCORE, LPLANE, NSIM, KPAR, LSCALAPACK, LSCAAWARE


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