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A series of Yb-substituted Zintl phases in the Ca 3- x Yb x AlSb 3 (0 ≤ x ≤ 0.81(1)) system has been synthesized by initial arc melting and post-heat treatment, and their isotypic crystal structures were characterized by both powder and single crystal X-ray diffraction analysis. All four title compounds adopted the Ca 3 AlAs 3 -type structure (space group Pnma , Pearson code oP 28, Z = 4). The overall structure can be described as a combination of the 1-dimensional (1D) infinite chain of ∞ 1 [Al(Sb 2 Sb 2/2 )] formed by two vertices sharing [AlSb 4 ] tetrahedral moieties and three Ca 2+ /Yb 2+ mixed sites located in between these 1D chains. The charge balance and the resultant independency of the 1D chains in the title system were explained by the Zintl-Klemm formalism [Ca 2+ /Yb 2+ ] 3 [(4b-Al 1- )(1b-Sb 2- ) 2 (2b-Sb 1- ) 2/2 ]. A series of DFT calculations proved that (1) the band overlap between the d -orbital states from two types of cations and the p -orbital states from Sb at the high symmetry Γ point implied a heavily doped degenerate semiconducting behavior of the quaternary Ca 2 YbAlSb 3 model and (2) the site preference of Yb for the M1 site was due to the electronic-factor criterion based on the Q values of each atomic site. The electron localization function calculations also proved that the two different shapes of lone pairs of the Sb atoms─the "umbrella-shape" and the "C-shape"─are determined by local geometry and the coordination environment on the anionic frameworks. Thermoelectric measurements of the quaternary title compound Ca 2.19(1) Yb 0.81 AlSb 3 showed an approximately two times larger ZT value than that of ternary Ca 3 AlSb 3 at 623 K due to increased electrical conductivity and ultralow thermal conductivity originated from Yb substitution for Ca.

Three Li- and Mg-cosubstituted compounds in the Gd 5- x (Li/Mg) x Ge 4 ( x = 1.04(2), 1.17(2), 1.53(2)) system have been successfully prepared by conventional high-temperature reactions. According to powder and single-crystal X-ray diffraction analyses, all three compounds adopt a Gd 5 Si 4 -type phase with the orthorhombic Pnma space group (Pearson code o P 16, Z = 4) and six crystallographically independent atomic sites. The crystal structure can be described as a combination of two-dimensional Mo 2 FeB 2 -type ∞ 2 [Gd 2 (Li/Mg)Ge 2 ] layers and [Ge 2 ] dimers. Interestingly, as 64% of Li and 26% of Gd at the RE3 and RE2 sites, respectively, were exclusively substituted by Mg in Gd 3.47(1) Li 0.36(2) Mg 1.17(3) Ge 4 , the lattice parameter b was selectively shortened as a result of the RE3-Ge1 bond shrinkage in comparison to that in Gd 4 LiGe 4 , while lattice parameters a and c remained nearly intact. A series of theoretical calculations using the tight-binding linear muffin-tin orbital (TB-LMTO) method indicated that the reduction of the particular RE3-Ge1 bond distance in the title compounds could also be explained by an optimization of bonding based on the corresponding RE3-Ge1 crystal orbital Hamilton population (COHP) curve. Moreover, the specific site preference of Mg for the RE3 site was supported by both size-factor as well as electronic-factor criteria on the basis of the smallest atomic size and the highest electronegativity of Mg among the three cations. Therefore, the overall electronic structure was further interrogated by a density of states (DOS) analysis. The influence of nonmagnetic Li/Mg cosubstitution for the magnetic Gd atoms in the title Gd 5- x (Li/Mg) x Ge 4 system on the magnetic characteristics was also thoroughly studied by isofield magnetization at 100 Oe and 10 kOe and isothermal magnetization measurements at 4 K using two of the title compounds: Gd 3.83(1) Li 0.48 Mg 0.69(3) Ge 4 and Gd 3.47(1) Li 0.36(2) Mg 1.17(3) Ge 4 .

Five ternary and quaternary Zintl phases in the solid-solution Ca 11- x A x Sb 10- y Ge z (A = Na, Li; 0.06(3) ≤ x ≤ 0.17(5), 0.19(1) ≤ y ≤ 0.55(1), 0.13(1) ≤ z ≤ 0.22(1)) system have been successfully synthesized by both of the arc-melting and the molten Pb metal-flux reactions. The crystal structure of these title compounds was characterized by powder and single-crystal X-ray diffractions analyses, and all title compounds crystallized in the Ho 11 Ge 10 -type phase in the tetragonal space group I 4/ mmm ( Z = 4, Pearson code tI 84). The complex crystal structure can be described as an assembly of 1) three kinds of cationic polyhedra centered by three different Sb and 2) the cage-shaped anionic frameworks built through the connection of two types of Sb. The newly substituted p -type double dopants of the cationic (Na and Li) and anionic (Ge) elements displayed particular site preferences, which were successfully explained by either the size-factor criterion based on the atomic size or the electronic-factor criterion based on the electronegativity of an element. Quite interestingly, as the reaction conditions were changed, the morphology shift of single crystals in Ca 10.94(3) Na 0.06 Sb 9.58(1) Ge 0.21 occurred from a cubic-shaped to a hummocky-type, to a hopper-type, and eventually to an octahedral-shaped crystal, just like the Yakutian kimberlite diamonds. Moreover, we firmly believe that the inclusion of the p -type Ge dopant for Sb was crucial to trigger this type of morphology shift and complete the octahedral-shaped morphology in the overall crystal-growth mechanism. The theoretical calculations using a DFT method rationalized the observed site preference of Na and the electronic effect of the p -type Ge dopants. The Seebeck coefficient measurements for Ca 10.88(4) Li 0.12 Sb 9.45(1) Ge 0.21 indicated that some portions of electron charge carriers were effectively eliminated by the p -type double dopants using Li and Ge.

A series of quaternary and quinary Zintl phase thermoelectric (TE) compounds, Ca 5- x Yb x Al 2- y In y Sb 6 (3.07(1) ≤ x ≤ 4.88(2); 0.16(2) ≤ y ≤ 2.00), containing Al/In mixed sites as well as Ca/Yb mixed sites has been successfully synthesized by a direct arc-melting method, and the X-ray diffraction analyses indicated that the products initially adopted an orthorhombic Ba 5 Al 2 Bi 6 -type structure (space group Pbam , Z = 2). However, after a postannealing process at 973 K for 1 month, the particular Yb rich compounds underwent a transformation of the original structure type to a Ca 5 Ga 2 Sb 6 -type phase regardless of the In substitution for Al. The noticeable site preference of cationic Ca and Yb in the three available cationic sites could be understood on the basis of a size match between the central cation and the volume of the anionic polyhedra. The observed phase transition was nicely explained by DFT calculations, proving that the Ca 5 Ga 2 Sb 6 -type phase was energetically more favorable than the Ba 5 Al 2 Sb 6 -type phase for the particular Yb-rich compound. Moreover, this energy difference between the two title phases was originally the result of both the site energy in the Ca site and the bond energies in the [(Al/In) 2 Sb 8 ] anionic building blocks. A series of thermoelectric property data indicated that a two-step process involving a partial/full In substitution for Al and a phase transition from the Ba 5 Al 2 Sb 6 -type to the Ca 5 Ga 2 Sb 6 -type phase successfully enhanced the electrical conductivities and the Seebeck coefficients of the title compounds. This kind of combined effect eventually resulted in a ZT improvement for the quinary compound Ca 1.14(2) Yb 3.86 Al 1.68(1) In 0.32 Sb 6 by approximately 4 times in comparison to its quaternary predecessor Ca 1.55(1) Yb 3.45 Al 2 Sb 6 .

Three Zintl phase compounds belonging to the CaYb 4 Al 2 Sb 6- x Ge x ( x = 0.2, 0.5, 0.7; nominal compositions) system with various Ge-doping contents were successfully synthesized by arc-melting and were initially crystallized in the Ba 5 Al 2 Bi 6 -type phase (space group Pbam, Pearson codes oP26). However, after post-heat treatment at an elevated temperature, the originally obtained crystal structure was transformed into the homeotypic Ca 5 Ga 2 Sb 6 -type structure according to powder and single-crystal X-ray diffraction analyses. Two types of crystal structures share some isotypic structural moieties, such as the one-dimensional anionic chains formed by ∞ 1 [Al 2 Sb 8 ] and the void-filling Ca 2+ /Yb 2+ mixed cations, but the slightly different spatial arrangements in each unit cell make these two structural types distinguishable. This series of title compounds is originally investigated to examine whether anionic p-type doping using Ge can successfully enhance thermoelectric (TE) properties of the Yb-rich CaYb 4 Al 2 Sb 6- x Ge x series even after the phase transition from the Ba 5 Al 2 Bi 6 -type to the Ca 5 Ga 2 Sb 6 -type phase. More interestingly, we also reveal that the given structural transformation is triggered by the particularly different site-preference of Ca 2+ and Yb 2+ among three available cationic sites in each structure type, which is significantly affected by thermodynamic conditions of this system. Band structure and density of states analyses calculated by density functional theory using the tight-binding linear muffin-tin orbital method also prove that the Ge-doping actually increases band degeneracies and the number of resonant peaks near the Fermi level resulting in the improvement of Seebeck coefficients. Electron localization function analyses for the (0 1 0) sliced-plane and the 3D isosurface nicely illustrates the distortion of the paired-electron densities due to the introduction of Ge. The systematic TE property measurements imply that the attempted anionic p-type doping is indeed effective to improve the TE characteristics of the title CaYb 4 Al 2 Sb 6- y Ge y system.

Two novel bismuth oxyfluoride nitrates, Bi 2 OF 3 (NO 3 ) and Bi 6 O 6 F 5 (NO 3 ), have been synthesized via hydrothermal reactions. Whereas Bi 2 OF 3 (NO 3 ) crystallizes in the centrosymmetric (CS) hexagonal space group, P6 3 / m, Bi 6 O 6 F 5 (NO 3 ) crystallizes in the polar noncentrosymmetric (NCS) trigonal space group, R3. The backbones of the title compounds reveal double layered structures composed of asymmetric BiF 3 (O/F) 3 or BiO 3 F 2 polyhedra and NO 3 trigonal planar groups. The diffuse reflectance spectra indicate that Bi 2 OF 3 (NO 3 ) and Bi 6 O 6 F 5 (NO 3 ) contain wide band gaps of 3.5 and 4.0 eV, respectively. Powder second-harmonic generation (SHG) measurements suggest that NCS Bi 6 O 6 F 5 (NO 3 ) is Type-I phase-matchable and has a large SHG response of ca. 3 times that of KH 2 PO 4 (KDP). Electron localization function (ELF) analysis indicates that the large SHG efficiency of Bi 6 O 6 F 5 (NO 3 ) is attributed to the synergistic effect of the alignment of NO 3 - trigonal planar groups and strong interactions between highly polarizable lone pair electrons on Bi 3+ and π-delocalized electrons in NO 3 - groups. Bi 2 OF 3 (NO 3 ) also exhibits a very good photocatalytic degradation efficiency of Rhodamine B (RhB) under the UV light irradiation.

A novel nonlinear optical (NLO) carbonatoperoxovanadate, Cs 3 VO(O 2 ) 2 CO 3 , with an exceptionally high thermostability was successfully synthesized by introducing highly polarizable Cs + cations and inorganic polydentate carbonate anions into asymmetric peroxovanadates. The structure of Cs 3 VO(O 2 ) 2 CO 3 is composed of distorted [VO(O 2 ) 2 CO 3 ] 3- units and charge balancing Cs + cations. The title compound exhibits the largest NLO intensity ever found in the current carbonate NLO materials, i. e., 23.0 times that of KH 2 PO 4 (KDP). The remarkably strong second-harmonic generation (SHG) response originates from the synergistic effect of the exceedingly polarizable Cs + cations, distortive polyhedra of the V 5+ cation, delocalized π orbitals in CO 3 groups, and distorted localized π orbitals in O 2 groups. First-principles calculations indicated that introducing the polarizable cations into peroxovanadates not only induces the enhancement of the SHG response but also improves the thermal stability of the framework.

A nonlinear optical (NLO) carbonatoperoxovanadate, Rb 3 VO(O 2 ) 2 CO 3 , was synthesized through a simple solution-evaporation method in phase-pure form. Single-crystal X-ray diffraction revealed that the structure of Rb 3 VO(O 2 ) 2 CO 3 consists of important noncentrosymmetric (NCS) chromophores, that is, π-delocalized (CO 3 ) 2- groups, a second-order Jahn-Teller (SOJT) distortive V 5+ cation, and π-localized distorted O 2 2- groups, as well as charge-balancing polarizable Rb + ions. The powder second-harmonic generation (SHG) measurements indicated that Rb 3 VO(O 2 ) 2 CO 3 is phase-matchable (Type I) and exhibits a remarkably strong SHG response circa 21.0 times that of potassium dihydrogen phosphate (KDP), which is the largest efficiency observed among carbonate NLO materials. First-principles calculation analysis suggests that the extremely large SHG response of Rb 3 VO(O 2 ) 2 CO 3 is attributed to the synergistic effect of the cooperation of all the constituting NCS chromophores., (© 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

A metastable tellurite, Li 2 Mo 3 TeO 12 , revealing a corrugated layered structure in an extremely strained coordination environment was hydrothermally synthesized in high yield. Li 2 Mo 3 TeO 12 undergoes Li + -exchange-driven facile structural transformation reactions to polyoxometalates. The kinetic data for the transformation reactions at various conditions were successfully obtained by simple lab-source powder X-ray diffraction. The investigation suggests that the solid-state transformation reactions may occur through a series of steps; substitution, decomposition, recombination, and precipitation. This new finding could be utilized in discovering functional metastable materials as well as understanding their phase transition mechanisms., (© 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Four polar intermetallic compounds belonging to the RE ₂In 1- x Li x Ge₂ ( RE = La, Nd, Sm, Gd; x = 0.13(1), 0.28(1), 0.43(1), 0.53(1)) system have been synthesized by the traditional solid-state reaction method, and their crystal structures have been characterized by single-crystal X-ray diffraction (SXRD) analyses. The isotypic crystal structures of four title compounds adopt the Mo₂FeB₂-type structure having the tetragonal space group P4/mbm ( Z = 2, Pearson code tP 40) with three crystallographically independent atomic sites and can be simply described as a pile of the identical 2-dimensioanl (2D) RE ₂In 1- x Li x Ge₂ slabs stacked along the c -axis direction. The substituting Li atom shows a particular site preference for replacing In at the Wyckoff 2 a site rather than Ge at the Wyckoff 4 g in this crystal structure. As the size of a used rare-earth metal decreases from La 3+ to Gd 3+ throughout the title system, the Ge-Ge and Ge-In/Li bond distances, both of which consist of the 2D anionic Ge₂(In/Li) layer, gradually decrease resulting in the reduction of a unit cell volume. A series of theoretical investigations has been performed using a hypothetical structure model Gd₂In 0.5 Li 0.5 Ge₂ by tight-binding linear muffin-tin orbital (TB-LMTO) method. The resultant densities of states (DOS) value at the Fermi level ( E F ) suggests a metallic conductivity for this particular composition, and this calculation result is in a good agreement with the formal charge distribution assigning two extra valence electrons for a metal-metal bond in the conduction band. The thorough analyses of six crystal orbital Hamilton population (COHP) curves representing various interatomic interactions and an electron localization function (ELF) diagram indicating the locations of paired-electron densities are also provided in this article., Competing Interests: The authors declare no conflict of interest. The founding sponsors had no role in the design of the study; in the collection, analyses, or interpretation of data; in the writing of the manuscript, and in the decision to publish the results.

Two Zintl phase thermoelectric compounds of Eu 11-x K x Bi 10-y Sn y (x = 0, 0.26(1); y = 0.86(2), 1.93(2)) have been synthesized by a high-temperature solid-state reaction and arc-melting methods. The two isotypic crystal structures are characterized by both single-crystal and powder X-ray diffractions, and adopt a tetragonal Ho 11 Ge 10 -type structure (space group I4/mmm, Z = 2, Pearson code tI84) containing nine crystallographically independent asymmetric atomic sites in a unit cell. The chemical compositions are confirmed by EDS analysis. The complex crystal structure of the two title compounds can be described as an assembly of three different types of co-facial polyhedra formed by cations and 3-dimensional anionic frameworks surrounding these polyhedra. A quaternary title compound, Eu 10.74(2) K 0.26 Bi 9.14(2) Sn 10.86 , which simultaneously contains both cationic and anionic p-dopants in a single compound, was successfully crystallized for the first time in the A 11 M 10 (A = alkaline-earth metals, rare-earth metals; M = triels, tetrels, pnictogens) series. In particular, two different types of p-dopants K and Sn show particular site-preferences, respectively, where K and Sn prefer to occupy the cationic Wyckoff 4e site and the anionic Wyckoff 8h site. These noticeable site preferences can be elucidated by either a size-factor criterion for the K-doping case or by an electronic-factor criterion for the Sn-doping case. The tight-binding linear muffin-tin orbital calculations show that as the double p-doping is applied to the Eu 11-x K x Bi 10-y Sn y system, some extra holes are generated on the electronic structures according to the density of states curves. However, a series of thermoelectric property measurements prove that this extra hole-carrier doping is hardly effective enough to completely suppress a bipolar conduction of holes and electrons due to the rigid metallic band structure of the title system.

The Zintl phase solid-solution Ca 11-x Yb x Sb 10-y Ge z (0 ≤ x ≤ 9; 0 ≤ y ≤ 3; 0 ≤ z ≤ 3) system with the cationic/anionic multisubstitution has been synthesized by molten Sn metal flux and arc-melting methods. The crystal structure of the nine title compounds were characterized by both powder and single-crystal X-ray diffractions and adopted the Ho 11 Ge 10 -type structure with the tetragonal space group I4/mmm (Z = 4, Pearson Code tI84). The overall isotypic structure of the nine title compounds can be illustrated as an assembly of three different types of cationic polyhedra sharing faces with their neighboring polyhedra and the three-dimensional cage-shaped anionic frameworks consisting of the dumbbell-shaped Sb 2 units and the square-shaped Sb 4 or (Sb/Ge) 4 units. During the multisubstitution trials, interestingly, we observed a metal-to-semiconductor transition as the Ca and Ge contents increased in the title system from Yb 11 Sb 10 to Ca 9 Yb 2 Sb 7 Ge 3 (nominal compositions) on the basis of a series of thermoelectric property measurements. This phenomenon can be elucidated by the suppression of a bipolar conduction of holes and electrons via an extra hole-carrier doping. The tight-binding linear muffin-tin orbital calculations using four hypothetical structural models nicely proved that the size of a pseudogap and the magnitude of the density of states at the Fermi level are significantly influenced by substituting elements as well as their atomic sites in a unit cell. The observed particular cationic/anionic site preferences, the historically known abnormalities of atomic displacement parameters, and the occupation deficiencies of particular atomic sites are further rationalized by the QVAL value criterion on the basis of the theoretical calculations. The results of SEM, EDS, and TGA analyses are also provided.

A meticulously designed, polar, non-centrosymmetric lead borate chloride, Pb2 BO3 Cl, was synthesized using KBe2 BO3 F2 (KBBF) as a model. Single-crystal X-ray diffraction revealed that the structure of Pb2 BO3 Cl consists of cationic [Pb2 (BO3 )](+) honeycomb layers and Cl(-) anions. Powder second harmonic generation (SHG) measurements on graded polycrystalline Pb2 BO3 Cl indicated that the title compound is phase-matchable (type I) and exhibits a remarkably strong SHG response, which is approximately nine times stronger than that of potassium dihydrogen phosphate, and the largest efficiency observed in materials with structures similar to KBBF. Further characterization suggested that the compound melts congruently at high temperature and has a wide transparency window from the near-UV to the mid-IR region., (© 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Four quaternary Zintl phases with mixed-cations in the Yb 14-x Ca x AlSb 11 (4.81 ≤ x ≤ 10.57) series have been synthesized by using the arc-melting and the Sn metal-flux reaction methods, and the isotypic crystal structures of the title compounds have been characterized by both powder and single-crystal X-ray diffraction (PXRD and SXRD) analyses. The overall crystal structure adopting the Ca 14 AlSb 11 -type can be described as a pack of four different types of the spiral-shaped one-dimensional octahedra chains with various turning radii, each of which is formed by the distorted ((Yb/Ca)Sb₆) octahedra. Four symmetrically-independent cationic sites contain mixed occupations of Yb 2+ and Ca 2+ with different mixing ratios and display a particular site preference by two cationic elements. Two hypothetical structural models of Yb₄Ca 10 AlSb 11 with different cationic arrangements were designed and exploited to study the details of site and bond energies. QVAL values provided the rationale for the observed site preference based on the electronegativity of each atom. Density of states (DOS) curves indicated a semiconducting property of the title compounds, and crystal orbital Hamilton population (COHP) plots explained individual chemical bonding between components. Thermal conductivity measurement was performed for Yb 8.42(4) Ca 5.58 AlSb 11 , and the result was compared to compounds without mixed cations.

Three quinary polar intermetallic compounds in the (Eu(1-x)Ca(x))9In8(Ge(1-y)Sn(y))8 (x = 0.66, y = 0.03) and the (Eu(1-x)Ca(x))3In(Ge(3-y)Sn(1+y)) (x = 0.66, 0.68; y = 0.13, 0.27) phases have been synthesized using the molten In-metal flux method, and the crystal structures are characterized by powder and single-crystal X-ray diffractions. Two orthorhombic structural types can be viewed as an assembly of polyanionic frameworks consisting of the In(Ge/Sn)4 tetrahedral chains, the bridging Ge2 dimers, either the annulene-like "12-membered rings" for the (Eu(1-x)Ca(x))9In8(Ge(1-y)Sn(y))8 series or the cis-trans Ge/Sn-chains for the (Eu(1-x)Ca(x))3In(Ge(3-y)Sn(1+y)) series, and several Eu/Ca-mixed cations. The most noticeable difference between two structural types is the amount and the location of the Sn-substitution for Ge: only a partial substitution (11%) occurs at the In(Ge/Sn)4 tetrahedron in the (Eu(1-x)Ca(x))9In8(Ge(1-y)Sn(y))8 series, whereas both a complete and a partial substitution (up to 27%) are observed, respectively, at the cis-trans Ge/Sn-chain and at the In(Ge/Sn)4 tetrahedron in the (Eu(1-x)Ca(x))3In(Ge(3-y)Sn(1+y)) series. A series of tight-binding linear muffin-tin orbital calculations is conducted to understand overall electronic structures and chemical bonding among components. Magnetic susceptibility measurement indicates a ferromagnetic ordering of Eu atoms below 5 K for Eu1.02(1)Ca1.98InGe2.87(1)Sn1.13.

Background/aims: The dose of mycophenolate mofetil (MMF) has been reduced in Asia due to side effects associated with the conventional fixed dose of 2-3 g/day. We aimed to determine the pharmacokinetics of a reduced dose of MMF and to validate its feasibility in combination with tacrolimus in living-donor liver transplantation (LDLT)., Methods: Two sequential studies were performed in adult LDLT between October 2009 and 2011. First, we performed a prospective pharmacokinetic study in 15 recipients. We measured the area under the curve from 0 to 12 hours (AUC(0-12)) for mycophenolic acid at postoperative days 7 and 14, and we performed a protocol biopsy before discharge. Second, among 215 recipients, we reviewed 74 patients who were initially administered a reduced dose of MMF (1.0 g/day) with tacrolimus (trough, 8-12 ng/mL during the first month, and 5-8 ng/mL thereafter), with a 1-year follow-up. We performed protocol biopsies at 2 weeks and 1 year post-LDLT., Results: In the first part of study, AUC(0-12) was less than 30 mgh/L in 93.3% of cases. In the second, validating study, 41.9% of the recipients needed dose reduction or cessation due to side effects within the first year after LDLT. At 12 months post-LDLT, 17.6% of the recipients were administered a lower dose of MMF (0.5 g/day), and 16.2% needed permanent cessation due to side effects. The 1- and 12-month rejection-free survival rates were 98.6% and 97.3%, respectively., Conclusions: A reduced dose of MMF was associated with low blood levels compared to the existing recommended therapeutic range. However, reducing the dose of MMF combined with a low level of tacrolimus was feasible clinically, with an excellent short-term outcome in LDLT.

Three new quaternary polar intermetallic compounds of Eu2.94(2)Ca6.06In8Ge8, Eu3.13(2)Ca5.87In8Ge8, and Sr3.23(3)Ca5.77In8Ge8 have been synthesized by a metal-flux method using molten indium metal as a reactive flux, and the novel isotypic crystal structures have been characterized by both powder and single-crystal X-ray diffractions. All compounds crystallize in the orthorhombic space group Pmmn (Z = 2, Pearson symbol oP50) with 14 crystallographically unique atomic positions in the asymmetric unit. The lattice parameters are refined as follows: a = 36.928(2) Å, b = 4.511(1) Å, and c = 7.506(1) Å for Eu2.94(2)Ca6.06In8Ge8; a = 37.171(19) Å, b = 4.531(2) Å, and c = 7.560(4) Å for Eu3.13(2)Ca5.87In8Ge8; and a = 37.350(2) Å, b = 4.550(3) Å, and c = 7.593(4) Å for Sr3.23(3)Ca5.77In8Ge8. In particular, single crystals of two Eu-containing compounds are obtained as bundles of bar/needle-shaped crystals, and the thicknesses of those crystals can be controlled in the range between ca. 300 μm and ca. <10 μm by adjusting several reaction conditions, including the reaction cooling rate and the centrifugation temperature. The overall crystal structure is illustrated as an assembly of (1) the three-dimensional anionic framework, which is formed by the chains of edge-sharing InGe4 tetrahedra and the annulene-like "12-membered anionic rings" connected via Ge2 dimers, and (2) the cationic mixed sites embedded in the space between the anionic frameworks. Theoretical investigations based on tight-binding linear muffin-tin orbital (TB-LMTO) calculations provide a comprehesive understanding of the overall electronic structure and chemical bonding observed among anionic components and between anions and cations. Electron localization function (ELF) and electron density map present chemical bond strengths and polarization within the anionic framework. Magnetic susceptibility measurement proves an antiferromagnetic (AFM) ordering of Eu atoms below 4 K with a reduced effective magnetic moment of 7.12 μB for the Eu atom.

The improvement of power conversion efficiency, especially current density (Jsc), for nanocrystal quantum dot based heterojunction solar cells was realized by employing a trenched ZnO film fabricated using nanoimprint techniques. For an optimization of ZnO patterns, various patterned ZnO films were investigated using electrical and optical analysis methods by varying the line width, interpattern distance, pattern height, and residual layer. Analyzing the features of patterned ZnO films allowed us to simultaneously optimize both the pronounced electrical effects as well as optical properties. Consequently, we achieved an enhancement in Jsc from 7.82 to 12.5 mA cm(-2) by adopting the patterned ZnO with optimized trenched shape.

The syntheses and single-crystal and electronic structures of three new ternary lithium rare earth germanides, RE(5-x)Li(x)Ge(4) (RE = Nd, Sm and Gd; x ≃ 1), namely tetrasamarium lithium tetragermanide (Sm(3.97)Li(1.03)Ge(4)), tetraneodymium lithium tetragermanide (Nd(3.97)Li(1.03)Ge(4)) and tetragadolinium lithium tetragermanide (Gd(3.96)Li(1.03)Ge(4)), are reported. All three compounds crystallize in the orthorhombic space group Pnma and adopt the Gd(5)Si(4) structure type (Pearson code oP36). There are six atoms in the asymmetric unit: Li1 in Wyckoff site 4c, RE1 in 8d, RE2 in 8d, Ge1 in 8d, Ge2 in 4c and Ge3 in 4c. One of the RE sites, i.e. RE2, is statistically occupied by RE and Li atoms, accounting for the small deviation from ideal RE(4)LiGe(4) stoichiometry.

A new polar intermetallic compound with a novel structure type has been synthesized and characterized by both powder and single-crystal X-ray diffraction. Ca(4)InGe(4) crystallizes in the monoclinic crystal system (space group C2/c, Z = 4, Pearson symbol mS36) with five crystallographically unique atomic positions in the asymmetric unit. The corresponding lattice parameters at 200(2) K are a = 18.452(8) Å, b = 5.819(2) Å, c = 8.339(3) Å, and β = 99.330(6)°. The overall crystal structure can be described as a linear intergrowth of two imaginary fragments--Ca(2)InGe(2) with the Gd(2)AlGe(2) type- and CaGe with the FeB type-structures. Another way to rationalize the bonding is to focus on the polyanionic framework, which in this case is made up of unique nets of "seesaw"-shaped [InGe(4)] units. They are interconnected via Ge-Ge dimers into an open three-dimensional framework with Ca(2+) cations occupying the voids within it. Tight-binding linear muffin-tin orbital (LMTO) calculations provide a rationale for the unique local coordination geometry around In and the two distinct types of Ge-Ge bond distances.

Eight new rare-earth metal-lithium-germanides belonging to the [REGe(2)](n)[RELi(2)Ge](m) homologous series have been synthesized and structurally characterized by single-crystal X-ray diffraction. The structures of the title compounds can be rationalized as linear intergrowths of imaginary RELi(2)Ge (MgAl(2)Cu structure type) and REGe(2) (AlB(2) structure type) slabs. The compounds with general formula RE(7)Li(8)Ge(10) (RE = La-Nd, Sm), i.e., [REGe(2)](3)[RELi(2)Ge](4), crystallize in the orthorhombic space group Cmmm (No. 65) with a new structure type. Similarly, the compounds with general formula RE(11)Li(12)Ge(16) (RE = Ce-Nd), i.e., [REGe(2)](5)[RELi(2)Ge](6), crystallize in the orthorhombic space group Immm (No. 71) also with its own structure type. Temperature-dependent DC magnetization measurements indicate Curie-Weiss paramagnetism in the high-temperature regime and hint at complex magnetic ordering at low temperatures. The measured effective moments are consistent with RE(3+) ground states in all cases. The experimental results have been complemented by tight-binding linear muffin-tin orbital (TB-LMTO) electronic structure calculations.

Reported are the syntheses, crystal structures, and magnetic susceptibilities of two series of closely related rare-earth metal-lithium germanides RE(2)Li(2)Ge(3) and RE(3)Li(4)Ge(4) (RE = La-Nd, Sm). All title compounds have been synthesized by reactions of the corresponding elements at high temperatures, and their structures have been established by single-crystal X-ray diffraction. RE(2)Li(2)Ge(3) phases crystallize in the orthorhombic space group Cmcm (No. 63) with the Ce(2)Li(2)Ge(3) structure type, while the RE(3)Li(4)Ge(4) phases crystallize in the orthorhombic space group Immm (No. 71) with the Zr(3)Cu(4)Si(4) structure type, respectively. Both of their structures can be recognized as the intergrowths of MgAl(2)Cu- and AlB(2)-like slabs, and these traits of the crystal chemistry are discussed. Temperature-dependent direct-current magnetization measurements indicate Curie-Weiss paramagnetism in the high-temperature regime for RE(2)Li(2)Ge(3) and RE(3)Li(4)Ge(4) (RE = Ce, Pr, Nd), while Sm(2)Li(2)Ge(3) and Sm(3)Li(4)Ge(4) exhibit Van Vleck-type paramagnetism. The data are consistent with the local-moment magnetism expected for RE(3+) ground states. At temperatures below ca. 20 K, magnetic ordering transitions have been observed. The experimental results have been complemented by tight-binding linear muffin-tin orbital electronic-band-structure calculations.

This article focuses on the synthesis and the crystal chemistry of six members of a series of rare-earth metal based germanides with general formula RELiGe(2) (RE = La-Nd, Sm, and Eu). The structures of these compounds have been established by single-crystal X-ray diffraction (CaLiSi(2) structure type, space group Pnma, Z = 4, Pearson symbol oP16). The chemical bonding within this atomic arrangement can be rationalized in terms of anionic germanium zigzag chains, conjoined via chains of edge-shared LiGe(4) tetrahedra and separated by rare-earth metal cations. The structure can also be viewed as an intergrowth of AlB(2)-like and TiNiSi-like fragments, or as the result of the replacement of 50% of the rare-earth metal atoms by lithium in the parent structure of the REGe monogermanides. Except for LaLiGe(2) and SmLiGe(2), the remaining four RELiGe(2) phases exhibit Curie-Weiss paramagnetism above about 50 K. In the low temperature regime, the localized 4f electrons in CeLiGe(2), PrLiGe(2), and SmLiGe(2) order ferromagnetically, while antiferromagnetic ordering is observed for NdLiGe(2) and EuLiGe(2). The calculated effective magnetic moments confirm RE(3+) ground states in all cases excluding EuLiGe(2), in which the magnetic response is consistent with Eu(2+) configuration (J = S = 7/2). The experimental results have been complemented by tight-binding linear muffin-tin orbital (TB-LMTO) band structure calculations.

The title compound, Yb(2)LiInGe(2), a new ordered quaternary inter-metallic phase, crystallizes with the ortho-rhom-bic Ca(2)LiInGe(2) type (Pearson code oP24). The crystal structure contains six crystallographically unique sites in the asymmetric unit, all in special positions with site symmetry .m.. The structure is complex and based on [InGe(4)] tetra-hedra, which share corners in two directions, forming layers parallel to (001). Yb atoms fill square-pyramidal (Yb1) and octa-hedral (Yb2) inter-stices between the [InGe(4/2)] layers, while the small Li(+) atoms fill tetra-hedral sites.

Reported are the synthesis and the structural characterization of two members of a new homologous series of polar intermetallic compounds, which exist only with mixed alkaline-earth and rare-earth metal cations. Crystals of (Eu(1-x)Ca(x))(4)In(3)Ge(4) (0.35(1)

The electronic structures of EuZn(2), Eu(Zn(0.75)Ge(0.25))(2), Eu(Zn(0.5)Ge(0.5))(2), Eu(Zn(0.25)Ge(0.75))(2), and EuGe(2) have been investigated using tight-binding, linear muffin-tin orbital (TB-LMTO) and pseudopotential methods to understand the structural preferences influenced by valence electron counts and to explain the observed homogeneity range of the AlB(2)-type phases as reported in the companion article. A crystal orbital Hamilton population (COHP) analysis for Zn-Zn contacts in EuZn(2) suggests a possible homogeneity width for the KHg(2)-type phase, which is indicated from analysis of X-ray powder diffraction patterns. Total electronic energy comparisons, as well as density of states (DOS) and COHP analysis for a hypothetical Zn-rich compound, Eu(Zn(0.75)Ge(0.25))(2), indicate that two distinct phases, KHg(2)-type EuZn(2) and AlB(2)-type Eu(Zn(1-x)Ge(x))(2) (0.5 < or = x < or = 0.70), are more favorable than a single Zn-rich composition adopting the AlB(2)-type phase. Among 10 structural models of Eu(Zn(0.5)Ge(0.5))(2), the one with heteroatomic Zn-Ge interactions both within and perpendicular to the 6(3) nets is energetically the most favorable structure. The experimentally observed Zn-Ge bond distance is attributed to the contribution of both sigma- and pi-bond interactions. Zn-Ge, Eu-Zn, and Eu-Ge COHP curves of the minimum energy form of Eu(Zn(0.5)Ge(0.5))(2) show bonding character above the Fermi level and explain the observed wide homogeneity width of the AlB(2)-type phase. In the Ge-rich case, Eu(Zn(0.25)Ge(0.75))(2), the planar hexagonal nets are not energetically favorable due to the significant antibonding character of Ge-Ge bonding at the Fermi level. Structural relaxation using pseudopotentials also revealed that the hexagonal nets tend to pucker rather than being planar, in agreement with the observed incommensurately modulated superstructure. An electron localization function analysis for Eu(Zn(0.5)Ge(0.5))(2) reveals that there exists no two-center, two-electron bond or multicentered interactions between interlayer Zn...Ge contacts.

The series of ternary polar intermetallics Eu(Zn(1-x)Ge(x))(2) (0 < or = x < or = 1) has been investigated and characterized by powder and single-crystal X-ray diffraction as well as physical property measurements. For 0.50(2) < or = x < 0.75(2), this series shows a homogeneity width of hexagonal AlB(2)-type phases (space group P6/mmm, Pearson symbol hP3) with Zn and Ge atoms statistically distributed in the planar polyanionic 6(3) nets. As the Ge content increases in this range, a decreases from 4.3631(6) A to 4.2358(6) A, while c increases from 4.3014(9) A to 4.5759(9) A, resulting in an increasing c/a ratio. Furthermore, the Zn-Ge bond distance in the hexagonal net drops from 2.5190(3) A to 2.4455(3) A, while the anisotropy of the displacement ellipsoids significantly increases along the c direction. For x < 0.50 and x > 0.75, respectively, orthorhombic KHg(2)-type and trigonal EuGe(2)-type phases occur as a second phase in mixtures with an AlB(2)-type phase. Diffraction of the x = 0.75(2) sample shows incommensurate modulation along the c direction; a structural model in super space group P3m1(00gamma)00s reveals puckered 6(3) nets. Temperature-dependent magnetic susceptibility measurements for two AlB(2)-type compounds show Curie-Weiss behavior above 40.0(2) K and 45.5(2) K with magnetic moments of 7.98(1) mu(B) for Eu(Zn(0.48)Ge(0.52(2)))(2) and 7.96(1) mu(B) for Eu(Zn(0.30)Ge(0.70(2)))(2), respectively, indicating a (4f)(7) electronic configuration for Eu atoms (Eu(2+)). The Zintl-Klemm formalism accounts for the lower limit of Ge content in the AlB(2)-type phases but does not identify the observed upper limit. In a companion paper, the intrinsic relationships among chemical structures, compositions, and electronic structures are analyzed by electronic structure calculations.

The ternary polar intermetallic compounds EuGaTt (Tt = Si, Ge, Sn) have been synthesized and characterized experimentally, as well as theoretically. EuGaSi crystallizes in the hexagonal AlB(2)-type structure (space group P6/mmm, Z = 1, Pearson symbol hP3) with randomly distributed Ga and Si atoms on the graphite-type planes: a = 4.1687(6) A, c = 4.5543(9) A. On the other hand, EuGaGe and EuGaSn adopt the hexagonal YPtAs-type structure (space group P6(3)/mmc, Z = 4, Pearson symbol hP12): a = 4.2646(6) A and c = 18.041(5) A for EuGaGe; a = 4.5243(5) A and c = 18.067(3) A for EuGaSn. The three crystal structures contain formally [GaTt](2-) polyanionic 3-bonded, hexagonal networks, which change from planar to puckered and exhibit a significant decrease in interlayer Ga-Ga distances as the size of Tt increases. Magnetic susceptibility measurements of this series of compounds show Curie-Weiss behavior above 86(5), 95(5), and 116(5) K with magnetic moments of 7.93, 7.97, and 7.99 mu(B) for EuGaSi, EuGaGe, and EuGaSn, respectively, indicating a 4f(7) electronic configuration (Eu(2+)) for Eu atoms. X-ray absorption spectra (XAS) are also consistent with these magnetic properties. Electronic structure calculations supplemented by a crystal orbital Hamilton population (COHP) analysis identifies the synergy between atomic sizes, from both Eu and Tt atoms, and the orbital contributions from Eu toward influencing the structural features of EuGaTt. A multicentered interaction between planes of Eu atoms and the [GaTt](2-) layers rather than through-space Ga-Ga bonding is seen in ELF distributions.