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We present a combined experimental and density functional theory study that characterizes the charge and spin density in NiX₂(3,5-lutidine)₄(X= Cl, Br and I). In this material, magnetic exchange interactions occur via Ni²⁺–halide...halide–Ni²⁺pathways, forming one-dimensional chains. We find evidence for weak halide...halide covalency in the iodine system, which is greatly reduced whenX= Br and is absent forX= Cl; this is consistent with the reported `switching-on' of magnetic exchange in the larger-halide cases. Our results are benchmarked against density functional theory calculations on [NiHF₂(pyrazine)₂]SbF₆, in which the primary magnetic exchange is mediated by F–H–F bridging ligands. This comparison indicates that, despite the largely depleted charge density found at the centre of halide...halide bonds, these through-space interactions can support strong magnetic exchange gated by weak covalency and enhanced by significant electron density overlapping that of the transition metal centres. 

Climate change represents a significant existential challenge in modern times, with widespread anxiety over its impacts. There's a growing desire among students to explore climate solutions and identify actions they can personally undertake to address climate change. Despite mitigation efforts, current greenhouse gas emission reduction measures are insufficient, and the development of negative emission technologies is both slow and costly. Consequently, the past two decades have witnessed an escalating interest in alternative strategies to temporarily and intentionally cool the planet. These strategies include injecting reflective particles into the stratosphere or increasing the reflectivity of low-lying ocean clouds. Collectively known as climate engineering, also called geoengineering, these approaches could serve as a temporary shield against the most severe outcomes of climate change, buying time while efforts to mitigate emissions and enhance carbon sequestration reach the required scale.In line with the Indiana state science standards (HS-ESS3-4), this article presents the Climate Engineering Teaching Module (CETM) and recounts firsthand experiences from its application in high school settings. Launched over three years ago, the CETM has been effectively integrated into fifteen Indiana classrooms. As the future citizens and leaders of Indiana, it is crucial that students are well-informed on climate engineering. Educating them about the scientific, ethical, political, and economic facets of climate engineering is imperative for fostering responsible decision-making. By examining the trade-offs associated with climate engineering and encouraging students to conceptualize ways to implement these technologies beneficially while minimizing risks, the CETM offers an innovative and practical approach to teaching climate change and engineering design. This method not only prepares students for active engagement in future discussions on climate engineering but also equips them with a comprehensive understanding of its complexities. 

The quasi-one-dimensional molecule-based Heisenberg antiferromagnet Cu(NO 3 ) 2 (pyz) 3 has an intrachain coupling J = 13.7(1) K ( ) and exhibits a state of long-range magnetic order below T N = 0.105(1) K. The ratio of interchain to intrachain coupling is estimated to be | J ′/ J | = 3.3 × 10 −3 , demonstrating a high degree of isolation for the Cu chains.