This article presents a model for local energy planning and its application in a full-scale experiment in a Swedish municipality. The model is based on legal requirement, research findings and standards of good practice and includes a combination of analytical and procedural tools intended to support rational decision-making: external scenarios, a citizens’ panel, life cycle analysis and qualitative environmental assessment (EA). The application of the model indicates that the decision-support tools selected can give several new and valuable inputs to local energy planning, such as local knowledge and values through citizen dialogue and comprehensive EAs. However, the experiment also shows that there are several challenges involved in applying the tools, for example, it is difficult to get citizens and the industry to participate and that it is complicated to combine several different tools for decision-making into a single planning process. Moreover, the experiences from the application suggest that the model for local energy planning show great potential but needs to be improved before it can be used as a standard of good practice.

Denna rapport ar en del av slutrapporteringen fran tva av projekten i programmet ”Miljostrategiska verktyg”. Projekten ar Utveckling av verktyg for strategisk miljobedomning och medborgarmedverkan ...

We present an investigation of the quasibinary systems CoIn3−xZnx and CoGa3−xZnx which were structurally characterized by X-ray diffraction experiments and, in the case of CoGa3−xZnx, additionally by neutron powder diffraction experiments. The limiting compositions were found to be x=0.81(2) and x=0.73(2) for CoIn3−xZnx and CoGa3−xZnx, respectively. The isotypic binary compounds CoIn3 and CoGa3 crystallize with the FeGa3 structure type (tetragonal, space group P42/mnm, Z=4) in which the p-block atoms form an array of columns of centered cubes defined by two different crystallographic sites. The substitution of In or Ga by Zn takes place in an ordered fashion and produces “colored” variants of the FeGa3 parent structure: In both systems Zn enters exclusively the position corresponding to the cube centers. Additionally, in CoIn3−xZnx this position is substituted in such a way that for a composition CoIn2.5Zn0.5, columns of Zn- and In-filled In8 cubes along the c axis alternate. The latter substitution pattern is accompanied by a symmetry lowering of the parent FeGa3 structure: The structure of CoIn3−xZnx is described by the space group P42/m in which the cube center position is split into two separate sites. By performing first-principles electronic structure calculations we investigated the general bonding situation of the compounds CoIn3 and CoGa3 and the particular electronic effect when incorporating Zn. With respect to the density of states of the binary compounds the exchange of Ga or In by Zn virtually affects only the electronic states just below the Fermi level. On increasing Zn concentration a dip is created in the density of states which approximately coincides with the location of the Fermi level for an electron count corresponding to limiting composition of the two systems.

The intermetallic compounds FeGa3 and RuGa3 were prepared from the elements using a Ga flux and their structures were refined from single-crystal X-ray data. Both compounds crystallize with the FeGa3 structure type (tetragonal, space group P42/mnm, Z=4). Electrical resistivity measurements revealed a semiconducting behavior for FeGa3 and RuGa3, which is in contrast to the good metallic conductivity observed for the isotypic compound CoGa3. The origin of the different electronic properties of these materials was investigated by first-principle calculations. It was found that in compounds adopting the FeGa3 structure type the transition metal atoms and Ga atoms interact strongly. This opens a d–p hybridization bandgap with a size of about 0.31 eV in the density of states at the Fermi level for 17-electron compounds (i.e., FeGa3 and RuGa3). The electronic structure of CoGa3 (an 18-electron compound) displays rigid band behavior with respect to FeGa3. As a consequence, the Fermi level in CoGa3 becomes located above the d–p hybridization gap which explains its metallic conductivity.

We present a detailed experimental and theoretical study concerning bonding and structural stability of intermetallic electron compounds with the ${\mathrm{PtHg}}_{4}$ structure. Due to the simplicity of the structure these compounds represent an excellent prototype system for a more general insight into bonding and stability of the large family of $d\ensuremath{-}sp$ bonded Hume-Rothery compounds. In particular, the representatives ${\mathrm{CrGa}}_{4}$ and ${\mathrm{MnGa}}_{4}$ were synthesised and their resistivity, magnetic susceptibility, and bulk modulus measured. We find that both compounds are metallic conductors but show a remarkable large difference in their temperature independent magnetic susceptibilities. The value of the Pauli paramagnetic susceptibility of ${\mathrm{MnGa}}_{4}$ is about $5\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}9}$ ${\mathrm{m}}^{3}/\mathrm{mol}$ higher than that of ${\mathrm{CrGa}}_{4}.$ The ${\mathrm{PtHg}}_{4}$ structure of ${\mathrm{CrGa}}_{4}$ and ${\mathrm{MnGa}}_{4}$ is stable up to pressures of about 100 kbar. Full-potential linearized augmented plane wave calculations reproduced very well the experimental structural properties of ${\mathrm{CrGa}}_{4}$ and ${\mathrm{MnGa}}_{4}$ and showed strong directional (covalent) bonding between transition metal atoms and Ga atoms in both compounds. The directional bonding is due to a large hybridization of the narrow d bands with the Ga $\mathrm{sp}$ bands. As a consequence a large pseudogap at the Fermi level for ${\mathrm{CrGa}}_{4}$ and slightly above the Fermi level for ${\mathrm{MnGa}}_{4}$ is produced. This pseudogap is characteristic and decisive for structural stability of electron compounds with the ${\mathrm{PtHg}}_{4}$ structure. We find that structural stability appears as a competition between optimizing the pseudogap and minimizing the compound equilibrium volume. Therefore, stable electron compounds are confined to systems $T{\mathrm{Ga}}_{4}$ with T being a transition metal from group 6 or 7. A complete substitution of Ga for isovalent Al or In is not possible.

The series of isotypic compounds V8Ga41 V8Ga36.9Zn4.1 Cr8Ga29.8Zn11.2 Mn8Ga27.4Zn13.6 with the V8Ga41 structure type (space group R3≈ , Z 3) was prepared and structurally characterised by X-ray diffraction experiments (V8Ga41: a 13.9351(5), c 14.8828(12); V8Ga36.9Zn4.1: a 13.9244(7), c 14.8660(9); Cr8Ga29.8Zn11.2: a 13.7153(5), c 14.6872(9); Mn8Ga27.4Zn13.6 : a 13.6033(6), c 14.6058(16)). The site occupancies of the ternary compounds were refined from neutron powder-diffraction data and exposed a startling segregation of Zn and Ga, which finally resulted in the formation of separated Zn13 cluster entities–corresponding to almost ideal centred cuboctahedra or small pieces of fcc metal±in the Mn compound, which has the highest Zn content in the series. The homogeneity ranges of the underlying phases T8Ga41 xZnx were determined to be 0 x 4.1(3), 8.7(3) x 11.2(3) and 13.6(4) x 16.5(3) for T V, Cr andMn, respectively. The different ranges of composition of the phases reflect the requirement of an optimum electron concentration for a stable V8Ga41-type structure, which is in the narrow range between 159 and 165 electrons per formula unit. First-principles electronic-structure calculations could explain this fact by the occurrence of a pseudo gap in the density of states at which the Fermi level is put for this particular electron concentration. Furthermore the nature of the Zn/Ga segregation was revealed: T±Zn interactions were found to be considerably weaker than those for T±Ga. This places the Zn atoms as far as possible from the T atoms, thus leading to the formation of cuboctahedral Zn13 entities.

The series of isotypic compounds V8Ga41 --> V8Ga36.9Zn4.1 --> Cr8Ga29.5Zn11.2 --> Mn8Ga27.4Zn13.6 with the V8Ga41 structure type (space group R3, Z = 3) was prepared and structurally characterised by X-ray diffraction experiments (V8Ga41: a 13.9351(5), 14.8828(12); V8Ga36.9Zn4.1: a = 13.9244(7), c = 14.8660(9): Cr8Ga29.8Zn11.2: 13.7153(5), c = 14.6872(9); Mn8Ga27.4Zn13.6: a = 13.6033(6), c = 14.6058(16)). The site occupancies of the ternary compounds were refined from neutron powder-diffraction data and exposed a startling segregation of Zn and Ga, which finally resulted in the formation of separated Zn13 cluster entities-corresponding to almost ideal centred cuboctahedra or small pieces of fcc metal-in the Mn compound, which has the highest Zn content in the series. The homogeneity ranges of the underlying phases T8Ga41 xZnx were determined to be 0 < x < 4.1(3), 8.7(3) < x < 11.2(3) and 13.6(4) < x < 16.5(3) for T = V, Cr and Mn, respectively. The different ranges of composition of the phases reflect the requirement of an optimum electron concentration for a stable V8Ga41-type structure, which is in the narrow range between 159 and 165 electrons per formula unit. First-principles electronic-structure calculations could explain this fact by the occurrence of a pseudo gap in the density of states at which the Fermi level is put for this particular electron concentration. Furthermore the nature of the Zn/Ga segregation was revealed: T-Zn interactions were found to be considerably weaker than those for T-Ga. This places the Zn atoms as far as possible from the T atoms, thus leading to the formation of cuboctahedral Zn13 entities.

Isolierte Clustereinheiten aus 13 Zn-Atomen treten unerwarteterweise in der Kristallstruktur von Mn8Ga27.4Zn13.6 auf (gezeigt ist das zentrale Bauelement der Verbindung). Sie entsprechen zentrierten Kuboktaedern, d. h. kleinen Volumina von kubisch-flächenzentriertem Metall. Die verblüffende Segregation von Ga- und Zn-Atomen in Mn8Ga27.4Zn13.6 wurde aus Rietveld-Verfeinerungen von Neutronen-Pulverstreuungsdaten ermittelt.

Separated Zn13 cluster entities unexpectedly occur in the solid-state structure of Mn8 Ga27.4 Zn13.6 (the central building block is shown). They correspond to centered cuboctahedra, that is, small volumes of face-centered cubic metal. The intriguing segregation of Ga and Zn atoms in Mn8 Ga27.4 Zn13.6 was verfied by Rietveld refinement of neutron powder diffraction data.

The purpose of this paper is to contribute to the search of for effective tools for public participation in general and public deliberation in specific in strategic environmental assessment (SEA) t ...