The 228 valence electron rule for onion-like inorganic fullerenes X1@Y12@Z20 of Ih and Th symmetry

Based on an analysis of the experimentally known 228e- valence electron systems AsNi12As203-, SbNi12Sb203-, SbPd12Sb203-, and SnCu12Sn2012- of Ih symmetry, the new species GeZn12Ge20, KrNi12As20, BrNi12As201-, SeNi12As202-, GeMn12Br20, SeCo12Se206+, and SeFe12Se206- have been designed according to the 228 electron rule introduced in this study for onion-like inorganic fullerenes composed of late main group and transition metal elements. Of these GeZn12Ge20, KrNi12As20, BrNi12As201-, SeNi12As202-, and GeMn12Br20 together with the known AsNi12As203- and its neutral counterpart were investigated at the DFT B3LYP/6-31G(d) level of theory. With one exception they show, in fact, two stable energetic minima of Ih and Th symmetry. Relaxing the symmetry constraints further, e.g. Y12 = {Q6,R6}, additional new neutral species of the general composition Z@Q6R6@Z20 of C5v and C2v symmetry can be formulated, i.e. Z = Se, Q = Fe, R = Mn, following this new building principle, therefore, supporting and inspiring the development of new materials of icosahedral and tetrahedral symmetry. Dedicated to Professor Helmut Schwarz on the occasion of his 80th birthda

3D climate modeling of Earth-like extrasolar planets orbiting different types of host stars

The potential habitability of a terrestrial planet is usually defined by the possible existence of liquid water on its surface. The potential presence of liquid water depends on many factors such as, most importantly, surface temperatures. The properties of the planetary atmosphere and its interaction with the radiative energy provided by the planet's host star are thereby of decisive importance. In this study we investigate the influence of different main-sequence stars upon the climate of Earth-like extrasolar planets and their potential habitability by applying a 3D Earth climate model accounting for local and dynamical processes. The calculations have been performed for planets with Earth-like atmospheres at orbital distances where the total amount of energy received from the various host stars equals the solar constant. In contrast to previous 3D modeling studies, we include the effect of ozone radiative heating upon the vertical temperature structure of the atmospheres. The global orbital mean results obtained have been compared to those of a 1D radiative convective climate model. The different stellar spectral energy distributions lead to different surface temperatures and due to ozone heating to very different vertical temperature structures. As previous 1D studies we find higher surface temperatures for the Earth-like planet around the K-type star, and lower temperatures for the planet around the F-type star compared to an Earth-like planet around the Sun. However, this effect is more pronounced in the 3D model results than in the 1D model because the 3D model accounts for feedback processes such as the ice-albedo and the water vapor feedback. Whether the 1D model may approximate the global mean of the 3D model results strongly depends on the choice of the relative humidity profile in the 1D model, which is used to determine the water vapor profile