Cover Image, Volume 118, Issue 1

For geometrically frustrated systems such as some neutral hydrogen rings, a variationally optimized single‐reference wave function breaks spin symmetry. This results in a non‐collinear magnetization density. The cover image depicts the norm of the non‐collinear magnetization density for three different hydrogen rings obtained with non‐collinear electronic structure methods. In e25398, Xiaosong Li and colleagues discuss how non‐collinear electronic structure theory is necessary for the accurate description of spin and magnetic phenomena whenever the spin symmetry of the electronic Hamiltonian is broken. The symmetry can be broken by geometric frustration, external magnetic fields, or spin‐orbit coupling. (DOI: 10.1002/qua.25398 )