spinw.basisvector method

generates lattice vectors

Syntax

basisVec = basisvector(obj, {norm})

Description

basisVec = basisvector(obj, {norm}) returns the lattice vectors of the unit cell in a $[3\times 3]$ matrix, with the $a$ , $b$ and $c$ vectors stored in columns. The vectors are normalized to the lattice parameters by default.

Examples

The basisVec matrix can be used to change coordinate system, converting between positions expressed in lattice units to positions expressed in Å, using r_lu for lattice unit coordinates and r_xyz for Å units (both stored in a column vector) the conversions are the following:

r_xyz = basisVec * r_lu

r_lu = inv(basisVec)*r_xyz

It is also possible to convert between momentum vector in reciprocal lattice units (rlu) into Å $^{-1}$ units. Assuming that momentum vectors are row vectors:

Q_xyz =  Q_rlu * 2*pi*inv(basisVec)

Q_rlu = 1/(2*pi)*Q_xyz*basisVect

Input Arguments

obj: spinw object.
norm: If true, the basis vectors are normalized to 1, otherwise the length of the basis vectors are equal to the lattice constants. Default is false.

Output Arguments

basisVec: Stores the three lattice vectors in columns, dimensions are $[3\times 3]$ .