Florez Edison, Smits Odile R, Mewes Jan-Michael, Jerabek Paul, Schwerdtfeger Peter
Centre for Theoretical Chemistry and Physics, The New Zealand Institute for Advanced Study, Massey University Auckland, Private Bag 102904, 0745 Auckland, New Zealand.
Mulliken Center for Theoretical Chemistry, University of Bonn, 53115 Bonn, Germany.
J Chem Phys. 2022 Aug 14;157(6):064304. doi: 10.1063/5.0097642.
As early as 1975, Pitzer suggested that copernicium, flerovium, and oganesson are volatile substances behaving like noble gas because of their closed-shell configurations and accompanying relativistic effects. It is, however, precarious to predict the chemical bonding and physical behavior of a solid by knowledge of its atomic or molecular properties only. Copernicium and oganesson have been analyzed very recently by our group. Both are predicted to be semiconductors and volatile substances with rather low melting and boiling points, which may justify a comparison with the noble gas elements. Here, we study closed-shell flerovium in detail to predict its solid-state properties, including the melting point, by decomposing the total energy into many-body forces derived from relativistic coupled-cluster theory and from density functional theory. The convergence of such a decomposition for flerovium is critically analyzed, and the problem of using density functional theory is highlighted. We predict that flerovium in many ways does not behave like a typical noble gas element despite its closed-shell 7p configuration and resulting weak interactions. Unlike the case of noble gases, the many-body expansion in terms of the interaction energy does not converge smoothly. This makes the accurate prediction of phase transitions very difficult. Nevertheless, a first prediction by Monte Carlo simulation estimates the melting point at 284 ± 50 K. Furthermore, calculations for the electronic bandgap suggests that flerovium is a semiconductor similar to copernicium.
早在1975年，皮策就提出，由于其闭壳层构型以及相关的相对论效应，鿔、镆和奥加涅森是具有类似稀有气体性质的挥发性物质。然而，仅通过了解其原子或分子性质来预测固体的化学键合和物理行为是不可靠的。我们小组最近对鿔和奥加涅森进行了分析。预计它们都是半导体和挥发性物质，熔点和沸点相当低，这可能证明与稀有气体元素进行比较是合理的。在这里，我们通过将总能量分解为源自相对论耦合簇理论和密度泛函理论的多体作用力，详细研究闭壳层的镆，以预测其固态性质，包括熔点。对镆这种分解的收敛性进行了严格分析，并突出了使用密度泛函理论的问题。我们预测，尽管镆具有闭壳层7p构型并由此产生弱相互作用，但在许多方面它的行为并不像典型的稀有气体元素。与稀有气体的情况不同，相互作用能的多体展开并不平滑收敛。这使得准确预测相变非常困难。尽管如此，蒙特卡罗模拟的首次预测估计熔点为284±50K。此外，对电子带隙的计算表明，镆是一种类似于鿔的半导体。
