Crystal Structures and Electronic Properties of BaAu Compound under High Pressure.

The investigations of Au-bearing alloy materials have been of broad research interest as their relevant features exhibit significant advantages compared with pure Au. Here, we extensively investigate the compression behaviors of BaAu compounds via first-principles calculations and find that a high-pressure cubic phase is calculated to be stable above 12 GPa. Further electronic calculations indicate that despite the low electronegativity of Ba, Fd-3m-structured BaAu exhibits metallic characteristics, which is different from those of semiconducting alkali metal aurides that possess slight characteristics of an ionic compound. These findings provide a step toward a further understanding of the electronic properties of BaAu compounds and provide key insight for exploring the other Au-bearing alloy materials under extreme conditions.

First-principles study on high-pressure phases and compression properties of gold-bearing intermetallic compounds.

Compared to elemental gold (Au), Au-based alloys have attracted wide attention for their economy and superior performance stemming from their distinctive physicochemical properties. The study of the structural characterization for alloy materials remains one of the fundamental issues associated with their future applications essentially. In this work, we theoretically explore some typical intermetallic compounds of Au-based alloys under high pressure, which has been an effective means to generate intriguing crystal configurations with unexpected behaviors. Ourab initiosimulations find thatFd-3m-AuRb,Fd-3m-AuBa, andFd-3m-AuLa become stable above ∼10 GPa, andPmmn-AuAl becomes stable above ∼20 GPa. Further investigations of their compression behaviors reveal that the bulk moduli of Au-based alloys can be greatly reduced by combining alkali and alkaline earth metals. The present results have unraveled the high-pressure phases of Au-bearing compounds and provide insights for exploring their important compressibility that is strongly relevant to the containing non-Au elements.

Regional ambient temperature is associated with human personality.

Human personality traits differ across geographical regions 1-5 . However, it remains unclear what generates these geographical personality differences. Because humans constantly experience and react to ambient temperature, we propose that temperature is a crucial environmental factor that is associated with individuals' habitual behavioural patterns and, therefore, with fundamental dimensions of personality. To test the relationship between ambient temperature and personality, we conducted two large-scale studies in two geographically large yet culturally distinct countries: China and the United States. Using data from 59 Chinese cities (N = 5,587), multilevel analyses and machine learning analyses revealed that compared with individuals who grew up in regions with less clement temperatures, individuals who grew up in regions with more clement temperatures (that is, closer to 22 °C) scored higher on personality factors related to socialization and stability (agreeableness, conscientiousness, and emotional stability) and personal growth and plasticity (extraversion and openness to experience). These relationships between temperature clemency and personality factors were replicated in a larger dataset of 12,499 ZIP-code level locations (the lowest geographical level feasible) in the United States (N = 1,660,638). Taken together, our findings provide a perspective on how and why personalities vary across geographical regions beyond past theories (subsistence style theory, selective migration theory and pathogen prevalence theory). As climate change continues across the world, we may also observe concomitant changes in human personality.