ALGO: Difference between revisions
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*{{TAG|ALGO}}=EVGW0 selects single-shot ''G''<sub>0</sub>''W''<sub>0</sub> calculations or partially | *{{TAG|ALGO}}=EVGW0 selects single-shot ''G''<sub>0</sub>''W''<sub>0</sub> calculations or partially self-consistent ''GW'' calculations. The orbitals (wavefunctions) of the previous groundstate calculations are maintained, and [[GW recipes#g0w0|G0W0 calculations]] are performed. If {{TAG|NELM}} is set, several iterations are performed, and the QP energies are updated in the calculation of ''G'' (for details see [[GW recipes#gw0|EVGW0 calculations]]). | ||
*{{TAG|ALGO}}=EVGW selects single-shot ''G''<sub>0</sub>''W''<sub>0</sub> calculations or partially | *{{TAG|ALGO}}=EVGW selects single-shot ''G''<sub>0</sub>''W''<sub>0</sub> calculations or partially self-consistent ''GW'' calculations. The orbitals of the previous groundstate calculations are maintained, and [[GW recipes#g0w0|G0W0 calculations]] are performed. If {{TAG|NELM}} is set, several iterations are performed, and the QP energies are updated in the calculation of ''G'' AND ''W'' (for details see [[GW recipes#gw0|EVGW calculations]]). | ||
*{{TAG|ALGO}}=QPGW0 selects | *{{TAG|ALGO}}=QPGW0 selects self-consistent ''GW'' calculations including off-diagonal components of the selfenergy. A full update of the QP energies AND one electron orbitals is performed in the calculation of ''G'' only (for details see [[GW recipes#scgw|QPGW0 calculations]]). | ||
*{{TAG|ALGO}}=QPGW selects | *{{TAG|ALGO}}=QPGW selects self-consistent ''GW'' calculations including off-diagonal components of the selfenergy. A full update of the QP energies AND one electron orbitals is performed in the calculations of ''G'' AND ''W'' (for details see [[GW recipes#scgw|QPGW calculations]]). | ||
Following tags are available as of VASP.6 | Following tags are available as of VASP.6 | ||
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*{{TAG|ALGO}}=ACFTDR synonym for RPAR (for details see [[ACFDT/RPA calculations#ACFDTR/RPAR|ACFDT/RPA calculations]]) | *{{TAG|ALGO}}=ACFTDR synonym for RPAR (for details see [[ACFDT/RPA calculations#ACFDTR/RPAR|ACFDT/RPA calculations]]) | ||
*{{TAG|ALGO}}= | *{{TAG|ALGO}}=EVGW0R selects low scaling version of EVGW0. The orbitals (wavefunctions) of the previous groundstate calculations are maintained and the QP energies are updated in the calculation of ''G''. {{TAG|NELM}} iterations are performed, ''e.g.'' for {{TAG|NELM}}=1 ''G''<sub>0</sub>''W''<sub>0</sub> calculations are selected (for details see [[GW recipes#gw0|EVGW0 calculations]]) | ||
*{{TAG|ALGO}}= | *{{TAG|ALGO}}=EVGWR selects low scaling version of EVGW. The orbitals (wavefunctions) of the previous groundstate calculations are maintained and the QP energies are updated in the calculation of ''G'' and ''W''. {{TAG|NELM}} iterations are performed (for details see [[GW recipes#scgw|EVGW calculations]]) | ||
*{{TAG|ALGO}}= | *{{TAG|ALGO}}=QPGW0R selects low scaling version of QPGW0. Quasi-particle ''GW'' calculations are performed, where off-diagonal components of the self-energy are included. A full update of the QP energies AND one electron orbitals is performed in the calculation of ''G'' only (for details see [[GW recipes#scgw0|QPGW0 calculations]]) | ||
*{{TAG|ALGO}}= | *{{TAG|ALGO}}=QPGWR selects low scaling version of QPGW. Quasi-particle ''GW'' calculations are performed, where off-diagonal components of the self-energy are included. A full update of the QP energies AND one electron orbitals is performed in the calculation of ''G'' and ''W'' (for details see [[GW recipes#scgw|QPGW calculations]]) | ||
*{{TAG|ALGO}}= | *{{TAG|ALGO}}=scGW0R selects self-consistent GW<sub>0</sub> calculations, where only the Green's function ''G'' is updated from the corresponding Dyson. The screened potential ''W'' remains unchanged after the first iteration. {{TAG|NELM}} iteration cycles are performed (see [[GW calculations#GWR|self-consistent GW calculations]]). | ||
*{{TAG|ALGO}}=scGWR selects self-consistent GW calculations, where both, ''G'' and ''W'' are updated from the corresponding Dyson equation. {{TAG|NELM}} iteration cycles are performed. (for details see [[GW calculations#GWR|self-consistent GW calculations]]). | |||
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Revision as of 10:52, 27 September 2017
ALGO = Normal | VeryFast | Fast | Conjugate | All | Damped | Subrot | Eigenval | None | Nothing | CHI | | G0W0 | GW0 | GW | scGW0 | scGW | G0W0R | GW0R | GWR | scGW0R | scGWR | ACFDT | RPA | ACFDTR | RPAR | BSE | TDHF
Default: ALGO = Normal
Description: the ALGO tag is a convenient option to specify the electronic minimisation algorithm (as of VASP.4.5) and/or to select the type of GW calculations.
- 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=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.
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.
ALGO for response functions and GW calculations and ACFDT/RPA calculations
Following tags are available as of VASP.5.X.
- ALGO=CHI calculates the response functions only.
- ALGO=TDHF selects TDHF calculations using the VASP internal Cassida code see BSE calculations, (available as of VASP.5.2.12)
- ALGO=BSE selects BSE calculations using the VASP internal Cassida code see BSE calculations
- ALGO=ACFDT selects RPA total energy calculations see ACFDT/RPA calculations
- ALGO=RPA synonymous to ACFDT see ACFDT/RPA calculations (available as of VASP.5.3.1)
GW tags have been renamed in VASP as follows
| < 5.2.12 | scGW | scGW0 | GW | GW0 | N/A | N/A |
|---|---|---|---|---|---|---|
| >= 5.2.12, < 6 | QPGW | QPGW0 | GW | GW0 | N/A | N/A |
| >= 6 | QPGW[R] | QPGW0[R] | EVGW[R] | EVGW0[R] | scGWR | scGW0R |
- ALGO=EVGW0 selects single-shot G0W0 calculations or partially self-consistent GW calculations. The orbitals (wavefunctions) of the previous groundstate calculations are maintained, and G0W0 calculations are performed. If NELM is set, several iterations are performed, and the QP energies are updated in the calculation of G (for details see EVGW0 calculations).
- ALGO=EVGW selects single-shot G0W0 calculations or partially self-consistent GW calculations. The orbitals of the previous groundstate calculations are maintained, and G0W0 calculations are performed. If NELM is set, several iterations are performed, and the QP energies are updated in the calculation of G AND W (for details see EVGW calculations).
- ALGO=QPGW0 selects self-consistent GW calculations including off-diagonal components of the selfenergy. A full update of the QP energies AND one electron orbitals is performed in the calculation of G only (for details see QPGW0 calculations).
- ALGO=QPGW selects self-consistent GW calculations including off-diagonal components of the selfenergy. A full update of the QP energies AND one electron orbitals is performed in the calculations of G AND W (for details see QPGW calculations).
Following tags are available as of VASP.6
- ALGO=RPAR selects low scaling RPA total energy calculations (for details see ACFDT/RPA calculations)
- ALGO=ACFTDR synonym for RPAR (for details see ACFDT/RPA calculations)
- ALGO=EVGW0R selects low scaling version of EVGW0. The orbitals (wavefunctions) of the previous groundstate calculations are maintained and the QP energies are updated in the calculation of G. NELM iterations are performed, e.g. for NELM=1 G0W0 calculations are selected (for details see EVGW0 calculations)
- ALGO=EVGWR selects low scaling version of EVGW. The orbitals (wavefunctions) of the previous groundstate calculations are maintained and the QP energies are updated in the calculation of G and W. NELM iterations are performed (for details see EVGW calculations)
- ALGO=QPGW0R selects low scaling version of QPGW0. Quasi-particle GW calculations are performed, where off-diagonal components of the self-energy are included. A full update of the QP energies AND one electron orbitals is performed in the calculation of G only (for details see QPGW0 calculations)
- ALGO=QPGWR selects low scaling version of QPGW. Quasi-particle GW calculations are performed, where off-diagonal components of the self-energy are included. A full update of the QP energies AND one electron orbitals is performed in the calculation of G and W (for details see QPGW calculations)
- ALGO=scGW0R selects self-consistent GW0 calculations, where only the Green's function G is updated from the corresponding Dyson. The screened potential W remains unchanged after the first iteration. NELM iteration cycles are performed (see self-consistent GW calculations).
- ALGO=scGWR selects self-consistent GW calculations, where both, G and W are updated from the corresponding Dyson equation. NELM iteration cycles are performed. (for details see self-consistent GW calculations).