We present a density-functional theory investigation of the electronic and magnetic properties of a linear chain model of the antiferromagnetic Cr 8 molecular ring. The chain model system is characterized by a smaller size of the simulation cell needed to perform the calculations, with respect to the one necessary for Cr 8 . By the thorough comparison between the model complex and the Cr 8 ring, we prove that the chain model is reliable and mimics with good approximation the electronic and magnetic properties of Cr 8 .

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A comprehensive study of electronic and magnetic properties of Cr8F8Piv16 (HPiv = pivalic acid, trimethyl acetic acid) molecular ring is presented. The total, local and orbital projected density of states are calculated by the first principle density functional theory calculations using the package SIESTA. The original molecule has been approximated by replacing the pivallic groups by H atoms (hydrogen saturation). Electron density, deformation density, electrostatic potential and spin density maps are analyzed and compared with experiment for the first time. Magnetic properties are investigated in detail. Magnetic moments are calculated using two different approaches: the Mulliken one and integration of muffin-tin sphere with a given radius. Different magnetic configurations (ferromagnetic, antiferromagnetic and many more with randomly distributed spins up and down) are considered to extract exchange interaction parameter J and check the stability of its estimate.

We report on a molecular dynamics study of small classical two-dimensional clusters with ringlike configurations. We focus on the particles motion at low temperatures before the radial and angular melting sets in. It is shown that in magic number configurations a local radial melting of subshells occur, which is related to the intershell rotation.