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Javier Junquera

Exercises on basis set generation Full control on the definition of the basis set functions: the PAO.Basis block. Javier Junquera. The PAO.Basis block Full control on the definition of the basis set. Species label :

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Javier Junquera

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  1. Exercises on basis set generation Full control on the definition of the basis set functions: the PAO.Basis block Javier Junquera

  2. The PAO.Basis block Full control on the definition of the basis set Specieslabel: determines thespeciesindexaccordingtothe block ChemicalSpecieslabel

  3. The PAO.Basis block Full control on the definition of the basis set Numberof shells of orbitalswithdifferent angular momentumforthecorrespondingchemicalspecies

  4. The PAO.Basis block Full control on the definition of the basis set As manyshells as indicatedhere

  5. The PAO.Basis block Full control on the definition of the basis set

  6. The PAO.Basis block Full control on the definition of the basis set Kind of basis set generationprocedure. Default: PAO.BasisType Split (seethelectureontheSplitNorm)

  7. Schemes to generate multiple- basis setsUse pseudopotential eigenfunctions with increasing number of nodes Advantages Orthogonal Asymptotically complete Disadvantages Excited states of the pseudopotentials, usually unbound Efficient depends on localization radii Availables in Siesta: PAO.BasisType Nodes T. Ozaki et al., Phys. Rev. B 69, 195113 (2004) http://www.openmx-square.org/

  8. The PAO.Basis block Full control on the definition of the basis set Onlyusedforthegeneration of thebasis set Default value 0.0 electrons

  9. Solving the Schrödinger equation for an ion for the generation of the basis set Extra charge Q Orbitals in anions tend to be more delocalized Orbitals in cations tend to be more localized (For instance, this parameter might be important in some oxides)

  10. The PAO.Basis block Full control on the definition of the basis set Thisflag determines whetherthesoft-confinementpotentialisused Default value: 0.0 Ry Default value: 0.0 Bohr Ifnegative, computed as thegivenfraction of the PAO cutoffradius.

  11. Soft-confinement potential Available in SIESTA J. Junquera et al., Phys. Rev. B 64, 235111 (2001) Prefactor of thesoft-confinementpotential Innerradiuswheretheshoft-confinementpotentialstarts off Advantages: orbital continuous with all the derivatives continuous diverges at rc(orbital exactly vanishes there) zero at the core region

  12. The PAO.Basis block Full control on the definition of the basis set As manycolumns as zetas in theshell Cutoffradius of ech zeta for a givenshell ( in Bohr)

  13. The numerical atomic orbitals are strictly localized: they are zero beyond a given cutoff radius Thisisthecutoffthatmight be explicitlyincluded in thePAO.Basis block

  14. The PAO.Basis block Full control on the definition of the basis set Ifsome of these are zero, thenthePAO.EnergyShiftorPAO.SplitNormwill be usedto determine thecutoff Forthesecon-zeta onwards, ifsome of these are negative, thenthe actual rcusedwill be thegivenfraction of thefirst

  15. The PAO.Basis block Full control on the definition of the basis set As manycolumns as zetas in theshell Constraint factor of each zeta. Default value 1.0

  16. The PAO.Basis block Full control on the definition of the basis set A shell of polarizationfunctions (with angular momentuml+1) will be constructedfromthefirst-zeta of angular mometuml (Default value: blank no polarizationorbitals) Number of zetas of thepolarizationshell

  17. The PAO.Basis block Full control on the definition of the basis set Ifthisflagis set to S, thefollowingnumbers sets thesplit-normparameterforthatshell Split NormParameterfortheshell

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