spinw.coupling property

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.