ALGO: Difference between revisions

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(Created page with '{{TAGDEF|ALGO|Normal {{!}} VeryFast {{!}} Fast {{!}} Conjugate {{!}} All {{!}} Damped {{!}} Subrot {{!}} Eigenval {{!}} None {{!}} Nothing|Normal}} Description: ---- ---- [[The_…')
 
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{{TAGDEF|ALGO|Normal {{!}} VeryFast {{!}} Fast {{!}} Conjugate {{!}} All {{!}} Damped {{!}} Subrot {{!}} Eigenval {{!}} None {{!}} Nothing|Normal}}
{{TAGDEF|ALGO|Normal {{!}} VeryFast {{!}} Fast {{!}} Conjugate {{!}} All {{!}} Damped {{!}} Subrot {{!}} Eigenval {{!}} None {{!}} Nothing|Normal}}


Description:
Description: the {{TAG|ALGO}} tag is a convenient option to specify the electronic minimisation algorithm in VASP.4.5 and later versions.
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*{{TAG|ALGO}}=Normal selects {{TAG|IALGO}}=38 (blocked Davidson iteration scheme).
*{{TAG|ALGO}}=VeryFast selects {{TAG|IALGO}}=48 (RMM-DIIS).
*{{TAG|ALGO}}=Fast selects a faily robust mixture of the Davidson and RMM-DIIS algorithms. In this case, Davidson ({{TAG|IALGO}}=38) is used for the initial phase, and then VASP switches to RMM-DIIS ({{TAG|IALGO}}=48). Subsequencly, for each ionic update, one {{TAG|IALGO}}=38 sweep is performed for each ionic step (except the first one).
*{{TAG|ALGO}}=Conjugate or {{TAG|ALGO}}=All selects an "all band simultaneous update of orbitals" ({{TAG|IALGO}}=58, in both cases the same conjugate gradient algorithm is used).
*{{TAG|ALGO}}=Damped selects a damped velocity friction algorithm ({{TAG|IALGO}}=53).
*{{TAG|ALGO}}=Subrot selects subspace rotation or diagonalization in the sub-space spanned by the orbitals ({{TAG|IALGO}}=4).
*{{TAG|ALGO}}=Eigenval allows to recalculate one electron energies, density of state and perform selected postprocessing using the current orbitals ({{TAG|IALGO}}=3) e.g. read from the {{FILE|WAVECAR}} file.
*{{TAG|ALGO}}=None or {{TAG|ALGO}}=Nothing allows to recalculate the density of states or perform selected postprocessing, using the current orbitals and one electron energies ({{TAG|IALGO}}=2) e.g. read from the {{FILE|WAVECAR}} file.
See next sections for details (6.44).
'''Mind''': except for 'None' and 'Nothing' (which must be spelled out), the first letter determines the applied algorithm. Conjugate, Subrot, Eigenval, None and Nothing are only supported by vasp.5.2.9 and newer versions.
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[[The_VASP_Manual|Contents]]
[[The_VASP_Manual|Contents]]


[[Category:INCAR]]
[[Category:INCAR]]

Revision as of 17:33, 29 January 2011

ALGO = Normal | VeryFast | Fast | Conjugate | All | Damped | Subrot | Eigenval | None | Nothing
Default: ALGO = Normal 

Description: the ALGO tag is a convenient option to specify the electronic minimisation algorithm in VASP.4.5 and later versions.


  • ALGO=Normal selects IALGO=38 (blocked Davidson iteration scheme).
  • ALGO=Fast selects a faily robust mixture of the Davidson and RMM-DIIS algorithms. In this case, Davidson (IALGO=38) is used for the initial phase, and then VASP switches to RMM-DIIS (IALGO=48). Subsequencly, for each ionic update, one IALGO=38 sweep is performed for each ionic step (except the first one).
  • ALGO=Conjugate or ALGO=All selects an "all band simultaneous update of orbitals" (IALGO=58, in both cases the same conjugate gradient algorithm is used).
  • ALGO=Damped selects a damped velocity friction algorithm (IALGO=53).
  • ALGO=Subrot selects subspace rotation or diagonalization in the sub-space spanned by the orbitals (IALGO=4).
  • ALGO=Eigenval allows to recalculate one electron energies, density of state and perform selected postprocessing using the current orbitals (IALGO=3) e.g. read from the WAVECAR file.
  • ALGO=None or ALGO=Nothing allows to recalculate the density of states or perform selected postprocessing, using the current orbitals and one electron energies (IALGO=2) e.g. read from the WAVECAR file.

See next sections for details (6.44).

Mind: except for 'None' and 'Nothing' (which must be spelled out), the first letter determines the applied algorithm. Conjugate, Subrot, Eigenval, None and Nothing are only supported by vasp.5.2.9 and newer versions.


Contents