Chemical bonding in equiatomic cerium intermetallics – The case of CeMgSn, CePdSn, and CeMgPb

• Properties of Sn and Pb based CeMgX and CePdSn are addressed within DFT methods.
• From charge transfer trends, the compounds are covalently bonded stannides and plumbides.
• Magnetic polarization on Ce within antiferromagnetic ground states.
• Chemical bonding analyses reveal the strongest interactions for Ce–Sn in CeMgSn, Ce–Pb in CeMgPb, and Ce–Pd in CePdSn.

The electronic and magnetic structures and the properties of chemical bonding in isopointal CeMgSn and CePdSn (both phases belong to the family of TiNiSi related intermetallics, space group Pnma) and CeMgPb belonging to the family of CeScSi intermetallics, space group I4/mmm, have been investigated within the density functional theory (DFT). The charge analyses indicate negatively charged tin and lead leading to assign the compounds as stannides and plumbides, as also illustrated by the mapping of the electron localization function ELF. Calculations within spin-degenerate non-magnetic spin-polarized ferro- (SP-F) and SP-antiferromagnetic configurations led to assign a major role of Ce 4f states in the onset of ordered moments within SP-AF ground states from energy differences. Chemical bonding analyses from crystal orbital overlap populations revealed the strongest interactions for Ce–Sn in CeMgSn, Ce–Pb in CeMgPb, and Ce–Pd in CePdSn.

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