calculates symbolic spin wave dispersion spectra = SPINWAVESYM(obj, 'option1', value1 ...) Symbolic spin wave dispersion is calculated as a function of reciprocal space points. The function can deal with arbitrary magnetic structure and magnetic interactions as well as single ion anisotropy and magnetic field. If the magnetic ordering wavevector is non-integer, the dispersion is calculated using a coordinate system rotating from cell to cell. In this case the Hamiltonian has to fulfill this extra rotational symmetry. The method works for incommensurate structures, however the calculated omega dispersion does not contain the omega(k+/-km) terms that has to be added manually. The method for matrix diagonalization is according to R.M. White, PR 139 (1965) A450. The non-Hermitian g*H matrix will be diagonalised. Input: obj Input structure, sw class object. Options: hkl Symbolic definition of q vector. Default is the general Q point: hkl = [sym('h') sym('k') sym('l')] eig If true the symbolic Hamiltonian is diagonalised. For large matrices (many magnetic atom per unit cell) this might be impossible. Set 'eig' to false to output only the quadratic Hamiltonian. Default is true. tol Tolerance of the incommensurability of the magnetic ordering wavevector. Deviations from integer values of the ordering wavevector smaller than the tolerance are considered to be commensurate. Default value is 1e-4. norm Whether to produce the normalized eigenvectors. It can be impossible for large matrices, in that case set it to false. Default is true. title Gives a title string to the simulation that is saved in the output.

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