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Pseudopotentials for SIESTA

SIESTA uses pseudopotentials to represent the electron-ion interaction (as do most plane-wave codes and in contrast to so-called "all-electron" programs). In particular, the pseudopotentials are of the "norm-conserving" kind.

Pseudopotentials in the PSF format

Versions of SIESTA before 5.0 use pseudopotential files in the 'Froyen' (psf) format. These pseudopotentials can be generated and tested by a number of programs, which include:

We used to provide a database of pseudopotentials in psf format, but we no longer do, as their quality was uneven. A database of pseudopotentials is still available at the Virtual Vault for Pseudopotentials site, but please remember that all pseudopotentials should be thoroughly tested before use. (See the standard literature on pseudopotentials and the user manuals for ATOM and other generation codes for more information on testing).

Curated pseudopotentials in the PSML format

In contrast, curated pseudopotential databases offer a higher level of testing and quality assurance. For example, the PseudoDojo is an open source project for developing and systematically testing pseudopotentials. These are generated with the multi-projector norm-conserving generator ONCVPSP, tested with seven different batteries of tests with ABINIT, and made available in a web-based database in several formats.

Users of SIESTA willing to try these pseudopotentials can use the new 5.0 (beta) version or the development version of SIESTA, which have support for the new PSML format.