File Applications/SpinW/m_files/sw_spinmotion.m

  calculates the amplitude and phase of spin motion
 
  SW_SPINMOTION(spectra, 'option1', value1 ...)
 
  It calculates the amplitude and phase of the local spin precessions
  belonging to a selected normal magnon mode.
 
  Options:
 
  iMagnon   Index of the normal magnon mode. Number has to be between one
            and nMagExt, the number of spins in the magnetic supercell.
            Default is the first magnon mode.
  Q         Momentum of the magnon in reciprocal lattice units (r.l.u.).
            Either a vector (Qh,Qk,Ql) where spectra is calculated with
            dimensions of [3 1], or scalar denoting the index of the Q
            point in the list of calculated Q points. Default is the first
            Q point.
 
  Output:
 
  Spectra contains an additional spectra.motion field with the following
  subfields:
 
  Amp1, Amp2    Orthogonal spin wave amplitude vectors for every spin in
                the magnetic supercell, dimensions are [3 nMagExt]. The
                selected normal magnon will create on the i-th spin a
                precession around the ground state direction along the
                ellipse defined by the Amp1(:,i) and Amp2(:,i) orthogonal
                vectors as major and minor axes. At t=0 the spin deviation
                vector points along Amp1.
  iQ            Index the magnon momentum, spectra.hkl(:,iQ) gives the
                magnon momentum in r.l.u. units.
  iMagnon       The index of the normal magnon mode.
  omega         Energy of the selected normal magnon mode. It gives also
 
  See also SW.SPINWAVE.