POSITIONS_ABS (.cell)

Keyword type

Block

Description

This data block contains the ionic positions in absolute coordinates.

The POSITIONS_ABS or POSITIONS_FRAC data block is interpreted as the reactant coordinate data for a transition state search.

The data block has the following format:

%BLOCK POSITIONS_ABS
[units]
	CCC1/I1     	R1x     R1y     R1z
	CCC2/I2 	    R2x     R2y     R2z
	.
	.
	.
%ENDBLOCK POSITIONS_ABS	

The first entry on a line is the symbol or atomic number of the ionic species. The correct symbol will be added automatically for atomic species if the atomic number is specified. A symbol can have a maximum of three characters.

The next three entries are real numbers representing the position of the ion in Cartesian coordinates.

[units] specifies the units in which the positions are defined. If no units are given, the default of Å is used.

Only one of POSITIONS_FRAC and POSITIONS_ABS may be present in a single cell file.

Example

%BLOCK POSITIONS_ABS
	.
	.
    O     6.2450000000   -2.3470000000    3.0440000000
    Al    5.7110000000    2.3470000000    5.0230000000
	.
	.
%ENDBLOCK POSITIONS_ABS
See Also:

POSITIONS_FRAC
CASTEP keyword glossary
CASTEP cell keywords and data blocks