SPECIES_POT (.cell)

Keyword type

Block

Description

This data block contains the names of the pseudopotential files associated with each species. It has the following format:

%BLOCK SPECIES_POT
	CCC1/I1 	[filename]
	CCC2/I2 	[filename]
	.
	.
	.
%ENDBLOCK SPECIES_POT

The first entry on a line is the symbol or atomic number of the species. This must correspond with the species symbol or atomic number of the species in the POSITIONS_FRAC or POSITIONS_ABS block. The second entry on each line is the name of the file containing the definition of the pseudopotential representing that ionic species.

The filename qualifier in the SPECIES_POT block may be either the name of the file that contains the tabulated pseudopotential on a grid (can be either ultrasoft or norm-conserving) or a text string containing the definition of the pseudopotential which is to be generated at runtime (on-the-fly generation).

Not all of the species present in the system have to appear in the SPECIES_POT block. Any that are not present will be assigned the default pseudopotential for that species, which will be generated on the fly. However, if the symbol specified for a species is not a standard symbol in the periodic table, the potential for the species must be specified.

The charge on the ion for each species will be derived from the pseudopotential corresponding to that ion.

Example

%BLOCK SPECIES_POT
       O  O_00.usp
      Al  Al_00.usp
      Ti  Ti_00.uspcc
      Cs  Cs_00.usp
%ENDBLOCK SPECIES_POT

See Also:

POSITIONS_FRAC
POSITIONS_ABS
CASTEP keyword glossary
CASTEP cell keywords and data blocks