Automatic calculation of symmetry-adapted tensors under spin-group symmetry. STENSOR, a new tool of the Bilbao Crystallographic Server

TL;DR

STENSOR is a new computational tool integrated into the Bilbao Crystallographic Server that automatically calculates symmetry-adapted tensors under spin group symmetry, aiding analysis of magnetic materials.

Contribution

The paper introduces STENSOR, a novel tool for automatic calculation of symmetry-adapted tensors under spin group symmetry, enhancing analysis of magnetic structures.

Findings

STENSOR computes symmetry-adapted tensors for magnetic compounds.

It distinguishes spin-orbit coupling effects from non-relativistic contributions.

The tool is demonstrated with illustrative examples.

Abstract

We present STENSOR, a new computational tool integrated into the Bilbao Crystallographic Server, designed for the automatic calculation of symmetry-adapted tensors under spin group symmetry. The program requires either a file containing the structural data of the magnetic compound or the generators of the oriented spin point group, together with the so-called generalized Jahn symbol associated to the tensor of interest. The user can propose any arbitrary tensor type or select a particular one from a predefined list. The program output returns the symmetry-adapted tensor under the spin point group and also under the magnetic point group, which is also calculated. The comparison of these two tensor forms allows to distinguish the coefficients that are due to spin-orbit coupling effects from those that have a non-relativistic origin and thus are usually more important. A couple of examples are given to illustrate the operation of the program.