PHONON_KPOINT_PATH (.cell)

Keyword type

Block

Description

This data block defines a path through reciprocal space, on which lie the k-points used for phonon calculations. It has the following format:

%BLOCK PHONON_KPOINT_PATH
	R1i     R1j     R1k 
	R<2i    R2j     R2k 
	.
	.
	.
%ENDBLOCK PHONON_KPOINT_PATH

The three numbers on each line are the fractional positions of the k-point relative to the reciprocal space lattice vectors. The k-points define a continuous sequence of straight line segments. The path will be open unless the first and last point in the list are identical.

The maximum spacing of the points sampled along each line segment is defined by PHONON_KPOINT_PATH_SPACING.

Example

%BLOCK PHONON_KPOINT_PATH
    0.3333333333    0.3750000000    0.3333333333
    0.3333333333    0.3750000000    0.0000000000
    0.3333333333    0.1250000000    0.3333333333
    0.3333333333    0.1250000000    0.0000000000
    0.0000000000    0.3750000000    0.3333333333
    0.0000000000    0.3750000000    0.0000000000
    0.0000000000    0.1250000000    0.3333333333
    0.0000000000    0.1250000000    0.0000000000
%ENDBLOCK PHONON_KPOINT_PATH

See Also:

PHONON_KPOINT_PATH_SPACING
CASTEP keyword glossary
CASTEP cell keywords and data blocks