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| effective_core_potentials [2024/07/12 08:37] – created - external edit 127.0.0.1 | effective_core_potentials [2024/10/25 16:06] (current) – prominent basis library link may |
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| ''ECP'',//atom//,[//ECP specification//] | ''ECP'',//atom//,[//ECP specification//] |
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| which defines a pseudopotential for an atom specified either by a chemical symbol or a group number. The //ECP specification// may consist either of a single keyword, which references a pseudopotential stored in the [[https://www.molpro.net/info/basis.php|library]], or else of an explicit definition (extending over several input cards), cf. below. | which defines a pseudopotential for an atom specified either by a chemical symbol or a group number. The //ECP specification// may consist either of a single keyword, which references a pseudopotential stored in the library, or else of an explicit definition (extending over several input cards), cf. below. |
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| ===== Input from ECP library ===== | ===== Input from ECP library ===== |
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| The [[https://www.molpro.net/info/basis.php|basis set library]] presently contains the pseudopotentials and associated valence basis sets by a) the Los Alamos group (P. J. Hay and W. R. Wadt, [[https://dx.doi.org/10.1063/1.448799|J. Chem. Phys.]] **82**, 270 (1985) and following two papers), and b) the Stuttgart/Köln group (e.g., A. Nicklass, M. Dolg, H. Stoll and H. Preuß, [[https://dx.doi.org/10.1063/1.468948|J. Chem. Phys.]] **102**, 8942 (1995); for more details and proper references, [[http://www.tc.uni-koeln.de/PP/index.en.html|click here]]). Pseudopotentials a) are adjusted to orbital energies and densities of a suitable atomic reference state, while pseudopotentials b) are generated using total valence energies of a multitude of atomic states. | The basis set library presently contains the pseudopotentials and associated valence basis sets by a) the Los Alamos group (P. J. Hay and W. R. Wadt, [[https://dx.doi.org/10.1063/1.448799|J. Chem. Phys.]] **82**, 270 (1985) and following two papers), and b) the Stuttgart/Köln group (e.g., A. Nicklass, M. Dolg, H. Stoll and H. Preuß, [[https://dx.doi.org/10.1063/1.468948|J. Chem. Phys.]] **102**, 8942 (1995); for more details and proper references, [[http://www.tc.uni-koeln.de/PP/index.en.html|click here]]). Pseudopotentials a) are adjusted to orbital energies and densities of a suitable atomic reference state, while pseudopotentials b) are generated using total valence energies of a multitude of atomic states. |
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| Library keywords in case a) are ''ECP1'' and ''ECP2''; ''ECP2'' is used when more than one pseudopotential is available for a given atom and then denotes the ECP with the smaller core definition. (For Cu, e.g., ''ECP1'' refers to an Ar-like 18$e^-$-core, while ''ECP2'' simulates a Ne-like 10$e^-$ one with the $3s$ and $3p$ electrons promoted to the valence shell). For accurate calculations including electron correlation, promotion of all core orbitals with main quantum number equal to any of the valence orbitals is recommended. | Library keywords in case a) are ''ECP1'' and ''ECP2''; ''ECP2'' is used when more than one pseudopotential is available for a given atom and then denotes the ECP with the smaller core definition. (For Cu, e.g., ''ECP1'' refers to an Ar-like 18$e^-$-core, while ''ECP2'' simulates a Ne-like 10$e^-$ one with the $3s$ and $3p$ electrons promoted to the valence shell). For accurate calculations including electron correlation, promotion of all core orbitals with main quantum number equal to any of the valence orbitals is recommended. |