Hartree-Fock theory for pseudorelativistic atoms

We study the Hartree-Fock model for pseudorelativistic atoms, that is, atoms where the kinetic energy of the electrons is given by the pseudorelativistic operator \sqrt{(pc)^2+(mc^2)^2}-mc^2. We prove the existence of a Hartree-Fock minimizer, and prove regularity away from the nucleus and pointwise exponential decay of the corresponding orbitals

Gold, friction and resistance in a globalised land system

In land system science (LSS), the globalisation of land use is often understood via trade flows. Fewer studies have explored the power asymmetries and local resistance that shape global connections. Consequently, calls for a deeper engagement with power and agency have been made within LSS. To accommodate this, we engage the ethnographic literature on encounters, emphasising the concepts of resistance and friction. These capture the ways actors position themselves in global systems, resist, and create global connections. To illustrate its relevance for land systems, we use qualitative data from the mining sector of Tanzania, highlighting the emergence of resource nationalism as an alternative form of globalisation (alter-globalisation). We argue that a focus on resistance, friction and alter-globalisation can move LSS towards a deeper engagement with power and agency in global flows, revealing the competing actors, values and visions embedded in land systems.Peer Reviewe

How Danish communal heat planning empowers municipalities and benefits individual consumers

Danish district heating has cost-effectively reduced the country's emissions. Danish heat planning has been critical to the district heating sector's success. Danish heat planning confers substantial power to municipalities. Empowering cities offers significant benefits to cities and consumers. Danish planning practices can be implemented today in the U.S. and other locations. a r t i c l e i n f o b s t r a c t Danish municipal heat planning empowers municipalities to implement locally appropriate energy solutions that are the best fit for the locality as a whole and the individual consumers served. Supportive policies and actions at the national and local levels have encouraged heat planning that confers significant autonomy to local governments. By examining how power is distributed and shared by different levels of governments in the planning process, this paper investigates how comprehensive energy planning in Denmark has supported the development of highly cost-effective district heating systems. Lessons from the Danish approach to heat planning are considered for their relevance to the United States, where significant technical district heating potential exists, yet remains well outside the typical energy policy discussions. While the specific Danish political context may not be transferable to other locations, the practical aspects of power sharing, socio-economic cost-benefit analyses, and communal decision-making may inform approaches to local heat planning around the world

Yes, one can obtain better quality structures from routine X-ray data collection

Single-crystal X-ray diffraction structural results for benzidine dihydrochloride, hydrated and protonated N,N,N,N-peri(dimethylamino)naphthalene chloride, triptycene, dichlorodimethyltriptycene and decamethylferrocene have been analysed. A critical discussion of the dependence of structural and thermal parameters on resolution for these compounds is presented. Results of refinements against X-ray data, cut off to different resolutions from the high-resolution data files, are compared to structural models derived from neutron diffraction experiments. The Independent Atom Model (IAM) and the Transferable Aspherical Atom Model (TAAM) are tested. The average differences between the X-ray and neutron structural parameters (with the exception of valence angles defined by H atoms) decrease with the increasing 2θmax angle. The scale of differences between X-ray and neutron geometrical parameters can be significantly reduced when data are collected to the higher, than commonly used, 2θmax diffraction angles (for Mo Kα 2θmax > 65°). The final structural and thermal parameters obtained for the studied compounds using TAAM refinement are in better agreement with the neutron values than the IAM results for all resolutions and all compounds. By using TAAM, it is still possible to obtain accurate results even from low-resolution X-ray data. This is particularly important as TAAM is easy to apply and can routinely be used to improve the quality of structural investigations [Dominiak (2015). LSDB from UBDB. University of Buffalo, USA]. We can recommend that, in order to obtain more adequate (more accurate and precise) structural and displacement parameters during the IAM model refinement, data should be collected up to the larger diffraction angles, at least, for Mo Kα radiation to 2θmax = 65° (sin θmax/λ < 0.75 Å−1). The TAAM approach is a very good option to obtain more adequate results even using data collected to the lower 2θmax angles. Also the results of translation–libration–screw (TLS) analysis and vibrational entropy values are more reliable for 2θmax > 65°