(properties)= # Properties The spinw object properties store all the information necessary for the spin wave calculation. It has 8 fields with several subfields, see below. (prop-lattice)= ## lattice stores the unit cell parameters ### Sub fields * `lat_const` : Lattice constants in a $[1\times 3]$ vector in units defined in [spinw.unit] (default value is \\ang). * `angle` : `[\\alpha,\\beta,\\gamma]` angles in a $[1\times 3]$ vector in radian units. * `sym` : Symmetry operators stored in matrix with dimensions of $[3\times 4 \times n_{op}]$. * `origin` : Origin of the cell in lattice units. * `label` : Label of the space group. (prop-unit-cell)= ## unit_cell Stores the atoms in the crystallographic unit cell ### Sub fields * `r` : Positions of the atoms in the unit cell, stored in a matrix with dimensions of $[3\times n_{atom}]$, values are in lattice units. * `S` : Spin quantum number of the atoms, stored in a row vector with $n_{atom}$ number of elements, non-magnetic atoms have `S=0`. * `label` : Label of the atom, strings stored in a $[1\times n_{atom}]$ cell. * `color` : Color of the atom stored in a matrix with dimensions of $[3\times n_{atom}]$, where every column defines an RGB color with values between 0 and 255. * `ox` : Oxidation number of the atom, stored in a $[1\times n_{atom}]$ matrix. * `occ` : Site occupancy in a $[1\times n_{atom}]$ matrix. * `b` : Scattering length of the atoms for neutron and x-ray stored in a $[2\times n_{atom}]$ matrix, first row is neutron, second row is for x-ray. * `ff` : Form factor of the site stored in a $[2\times 9\times n_{atom}]$ matrix, first row is the magnetic form factor for neutrons, the second row is the charge form factor for x-ray cross section. * `Z` : Atomic number in a row vector. * `A` : Atomic mass (N+Z) for isotopes and -1 for natural distribution of isotopes stored in a row vector. * `biso` : Isotropic displacement factors in units of \\ang$^2$. Definition is the same as in [FullProf](https://www.ill.eu/sites/fullprof/), defining the Debye-Waller factor as $W(d) = 1/8*b_{iso}/d^2$ which is included in the structure factor as $\exp(-2W(d))$. (prop-twin)= ## twin stores the crystal twin parameters ### Sub fields * `rotc` : Rotation matrices in the $xyz$ coordinate system for every twin, stored in a matrix with dimensions of $[3\times 3\times n_{twin}]$. * `vol` : Volume ratio of the different twins, stored in a row vector with $n_{twin}$ elements. (prop-matrix)= ## matrix stores 3x3 matrices for using them in the Hamiltonian ### Sub fields * `mat` : Stores the actual values of 3x3 matrices, in a matrix with dimensions of $[3\times 3\times n_{matrix}]$, if assigned for a bond, the unit of energy is stored in [spinw.unit] (default value is meV). * `color` : Color assigned for every matrix, stored in a matrix with dimensions of $[3\times n_{matrix}]$, with each column defining an RGB value. * `label` : Label for every matrix, stored as string in a cell with dimensions of $[1\times n_{matrix}]$. (prop-single-ion)= ## single_ion stores single ion terms of the Hamiltonian ### Sub fields * `aniso` : Row vector that contains $n_{magatom}$ integers, each integer assignes one of the matrices from the [spinw.matrix] property to a magnetic atom in the generated [spinw.matom] list as a single ion anisotropy. Zero value of `aniso` means no single ion anisotropy for the corresponding magnetic atom. * `g` : Row vector with $n_{magatom}$ integers, each integer assignes one of the matrices from the [spinw.matrix] property to a magnetic atom in the spinw.matom list as a g-tensor. Zero value of `g` means a default g-value of 2 for the corresponding atoms. * `field` : External magnetic field stored in a row vector with 3 elements, unit is defined in [spinw.unit] (default unit is Tesla). * `T` : Temperature, scalar, unit is defined in [spinw.unit] (default unit is Kelvin). (prop-coupling)= ## coupling stores the list of bonds ### Sub fields * `dl` : Distance between the unit cells of two interacting spins, stored in a $[3\times n_{coupling}]$ matrix. * `atom1` : First magnetic atom, pointing to the list of magnetic atoms in the list generated by `spinw.matom`, stored in a row vector with $n_{coupling}$ element. * `atom2` : Second magnetic atom, same as `atom1`. * `mat_idx` : Stores pointers to matrices for every coupling in a $[3\times n_{coupling}]$ matrix, maximum three matrix per coupling (zeros for no coupling) is allowed. * `idx` : Neighbor index, increasing indices for the equivalent couplings, starting with 1,2,... which means first and second neighbor bonds, respectively. * `type` : Type of coupling corresponding to `mat_idx` matrices. Default is 0 for quadratic exchange, `type = 1` for biquadratic exchange. * `sym` : If `true` the bond symmetry operators will be applied on the assigned matrix. * `rdip` : Maximum distance until the dipolar interaction is calculated. Zero value means no dipolar interactions are considered. * `nsym` : The largest bond `idx` value that is generated using the space group operators. Typically very long bonds for dipolar interactions won't be calculated using space group symmetry. (prop-mag-str)= ## mag_str stores the magnetic structure ### Sub fields * `F` : Complex magnetization (strictly speaking complex spin expectation value) for every spin in the magnetic cell, represented by a matrix with dimensions of $[3\times n_{magext}\times n_k]$, where `nMagExt = nMagAtom*prod(N_ext)` and $n_k$ is the number of the magnetic propagation vectors. * `k` : Magnetic propagation vectors stored in a matrix with dimensions of $[3\times n_k]$. * `N_ext` : Size of the magnetic supercell in lattice units, default value is `[1 1 1]` emaning that the magnetic cell is identical to the crystallographic cell. The $[1\times 3]$ vector extends the cell along the $a$, $b$ and $c$ axes. (prop-unit)= ## unit stores the physical units for the Hamiltonian Default values are meV, T, $\unicode{x212B}$ and K for energy, magnetic field, length and temperature, respectively. ### Sub fields * `kB` : Boltzmann constant, default value is 0.0862 meV/K. * `muB` : Bohr magneton, default values is 0.0579 meV/T. * `mu0` : Vacuum permeability, default value is 201.335431 T$^2\unicode{x212B}^3$/meV. * `label` : Labels for distance, energy, magnetic field and temperature stored in a cell with dimensions $[1\times 4]$. * `nformula` : Number of formula units in the unit cell. * `qmat` : Transformation matrix that converts the given $Q$ values into the internal reciprocal lattice. The matrix has dimensions of $[3\times 3]$. ## cache stores temporary values This property should be only used to check consistency of the code. {% include warning.html content="Changing these values is strongly discouraged as it can break the code!" %} ### Sub fields * `matom` : Generated data of the magnetic unit cell. * `symop` : Generated symmetry operators for each bond.