Alkaline earth mono-silicides ({\AE}Si, {\AE} = Ca, Sr, Ba) are poor metals and their transport properties are not solely determined by the Zintl anion, in contrast to their Zintl-type composition. Their conducting network is formed by the depopulated ∞1[Si2−] π-system and {\AE}-d states. This justifies the special local coordination of the metal atoms and the planarity of the silicon chains. The low density of carriers seems to be a playground for magnetic instabilities and the triangular prismatic arrangement of {\AE} atoms responsible for the observed weak glassy behavior.
@article{arxiv.0909.0434,
title = {Unexpected Magnetism in Alkaline Earth Mono-Silicides},
author = {Eduardo Cuervo-Reyes and Elizabeth Diane Stalder and Christian Mensing and Serhiy Budnyk and Reinhard Nesper},
journal= {arXiv preprint arXiv:0909.0434},
year = {2012}
}