F − (H 2 O) n  (n=1–6) clusters have been studied using ab initio calculations. This is an extensive work to search for various low-lying energy conformers, for example, including 13 conformers for n=6. Our predicted enthalpies and free energies are in good agreement with experimental values. For n=4 and 6, both internal and surface structures are almost isoenergetic at 0 K, while internal structures are favored with increasing temperature due to the entropic effect. For n=5, the internal structure is favored at both 0 and 298 K under 1 atm. These are contrasted to the favored surface structures in other small aqua–halide complexes. The ionization potential, charge-transferto-solvent (CTTS) energy, and O–H stretching vibrational spectra are reported to facilitate future experimental work. Many-body interaction potential analyses are presented to help improve the potential functions used in molecular simulations. The higher order many-body interaction energies are found to be important to compare the energetics of the various conformers and compare the stability of the internal over the surface state.

This paper introduces a bi‐objective strategic location problem to address access and coverage. While previous research in continuous location modelling considered access coverage independently, none has approached such a problem in an integrated fashion. In this paper, a new mathematical formulation considering access and coverage is derived, and a solution algorithm to find the entire set of optimal tradeoff solutions is developed. Application findings are reported for several case studies, varying in problem size. The developed approach is shown to provide critical insights for real‐time decision‐making, facilitating planning, management and policy development.

Spatial optimization involving multiple objectives is com mon ly needed to address complex planning and management issues yet associated models and problems are excep tionally difficult and complicated to solve. Opensource approaches have received attention because they offer potential for making spatial optimization more broadly avail able, and other GIScience methods, to support analysis and decisionmaking. Beyond this, the ability to integrate GISci ence functions through opensource alternatives offers great potential to decrease reliance on commercial, proprie tary software as well as enable broader use and adoption of, and reliance on, spatial optimization approaches. This article details an important biobjective spatial problem along with opensource capabilities for solution as an example of chal lenges faced and opportunities possible. A number of solu tion approaches are considered, providing an opportunity to assess computational requirements, functionality, solution quality and issues encountered. Empirical applications asso ciated with emergency response, healthcare access, food processing and strategic player positioning are detailed. This study highlights capabilities, limitations and challenges for opensource science in addressing a class of multiobjective spatial optimization problems.

No abstract

There has been much concern for sustainability issues, recognizing the significant impacts that humans have had and continue to have on the Earth. Urban informatics has much to offer city systems in terms of understanding, management and design, particularly associated with sustainability. Efficiency that characterizes sustainable systems, and strategic goals to achieve them, does not happen by chance, but rather is the byproduct of concerted efforts driven by informed decision making. This paper focuses on strategic decision making, and the role of spatial optimization as a component of urban informatics. Strategic siting involving access and coverage demonstrates the capabilities of spatial optimization, but more importantly highlights the significance of an urban informatics perspective.