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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 18e−-core, while ''ECP2'' simulates a Ne-like 10e− 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 18e−-core, while ''ECP2'' simulates a Ne-like 10e− 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. |