Positions Of Oxygen Atoms Research Articles

Structural basis of selective beta-carotene binding by a soluble protein

β-carotene (BCR) is the most abundant carotenoid, a colorant, antioxidant, and provitamin A. The extreme hydrophobicity of this hydrocarbon requires special mechanisms for distribution in aqueous media, including water-soluble carotenoproteins. However, all known carotenoproteins prefer oxygenated carotenoids and bind BCR inefficiently. Here, we present the crystal structure of the BCR-binding protein (BBP) from gregarious male locusts, which is responsible for their vivid yellow body coloration, in complex with its natural ligand, BCR. BBP forms an antiparallel tubular homodimer with α/β-wrap folded monomers, each forming a hydrophobic 47Å long, coaxial tunnel that opens outward and is occupied by one s-cisC6-C7, all-trans BCR molecule. In the BCR absence, BBP accepts a range of xanthophylls, with reduced efficiency depending on the position and number of oxygen atoms, but rejects lycopene. The structure captures a pigment complex with a Takeout 1 protein and inspires potential applications of BBP as a BCR solubilizer.

Stoichiometric reconstruction of the Al2O3(0001) surface.

Macroscopic properties of materials stem from fundamental atomic-scale details, yet for insulators, resolving surface structures remains a challenge. We imaged the basal (0001) plane of α-aluminum oxide (α-Al2O3) using noncontact atomic force microscopy with an atomically defined tip apex. The surface formed a complex ([Formula: see text] × [Formula: see text])R±9° reconstruction. The lateral positions of the individual oxygen and aluminum surface atoms come directly from experiment; we determined with computational modeling how these connect to the underlying crystal bulk. Before the restructuring, the surface Al atoms assume an unfavorable, threefold planar coordination; the reconstruction allows a rehybridization with subsurface O that leads to a substantial energy gain. The reconstructed surface remains stoichiometric, Al2O3.

Tilting and Distortion in the Multiferroic Aurivillius Phase Bi6Ti3Fe1.5Mn0.5O18.

Aurivillius structured Bi6Ti3Fe1.5Mn0.5O18 (B6TFMO) has emerged as a rare room temperature multiferroic, exhibiting reversible magnetoelectric switching of ferroelectric domains under cycled magnetic fields. This layered oxide presents exceptional avenues for advancing data storage technologies owing to its distinctive ferroelectric and ferrimagnetic characteristics. Despite its immense potential, a comprehensive understanding of the underlying mechanisms driving multiferroic behavior remains elusive. Herein, we employ atomic resolution electron microscopy to elucidate the interplay of octahedral tilting and atomic-level structural distortions within B6TFMO, associating these phenomena with functional properties. Fundamental electronic features at varying bonding environments within this complex system are scrutinized using electron energy loss spectroscopy (EELS), revealing that the electronic nature of the Ti4+ cations within perovskite BO6 octahedra is influenced by position within the Aurivillius structure. Layer-by-layer EELS analysis shows an ascending crystal field splitting (Δ) trend from outer to center perovskite layers, with an average increase in Δ of 0.13 ± 0.06 eV. Density functional theory calculations, supported by atomic resolution polarization vector mapping of B-site cations, underscore the correlation between the evolving nature of Ti4+ cations, the extent of tetragonal distortion and ferroelectric behavior. Integrated differential phase contrast imaging unveils the position of light oxygen atoms in B6TFMO for the first time, exposing an escalating degree of octahedral tilting toward the center layers, which competes with the magnitude of BO6 tetragonal distortion. The observed octahedral tilting, influenced by B-site cation arrangement, is deemed crucial for juxtaposing magnetic cations and establishing long-range ferrimagnetic order in multiferroic B6TFMO.

HydraProt: A New Deep Learning Tool for Fast and Accurate Prediction of Water Molecule Positions for Protein Structures.

Water molecules are integral to the structural stability of proteins and vital for facilitating molecular interactions. However, accurately predicting their precise position around protein structures remains a significant challenge, making it a vibrant research area. In this paper, we introduce HydraProt (deep Hydration of Proteins), a novel methodology for predicting precise positions of water molecule oxygen atoms around protein structures, leveraging two interconnected deep learning architectures: a 3D U-net and a Multi-Layer Perceptron (MLP). Our approach starts by introducing a coarse voxel-based representation of the protein, which allows for rapid sampling of candidate water positions via the 3D U-net. These water positions are then assessed by embedding the water-protein relationship in the Euclidean space by means of an MLP. Finally, a postprocessing step is applied to further refine the MLP predictions. HydraProt surpasses existing state-of-the-art approaches in terms of precision and recall and has been validated on large data sets of protein structures. Notably, our method offers rapid inference runtime and should constitute the method of choice for protein structure studies and drug discovery applications. Our pretrained models, data, and the source code required to reproduce these results are accessible at https://github.com/azamanos/HydraProt.

The Adsorption Behavior of Hydrogen on the PuO2(111) Surface: A DFT+U Study

Based on density functional theory, a first-principles study of the adsorption behavior of hydrogen atoms on the PuO2(111) surface is carried out in this work. Models for three different surface morphologies of PuO2(111) are established. It is found that the surface with the outermost oxygen atom (sub outer Pu atom) morphology has the best stability. Based on this model, the adsorption energy, bader charge, and electronic density of the states of a hydrogen atom at different adsorption sites are calculated. Finally, we analyzed the process of hydrogen dissociation into hydrogen atoms on the surface using the cNEB method. The results indicate that the top position of the outermost oxygen atom and the bridge position of the second outermost plutonium atom are relatively stable adsorption configurations, where hydrogen atoms lose electrons and release heat, forming O-H bonds with oxygen atoms. The density of states of O-p orbital electrons will undergo significant changes, reflecting the hybridization of O-p and H-s orbital electrons, forming a stable bonding effect. The dissociation of hydrogen molecules into two hydrogen atoms adsorbed on the top of oxygen atoms requires crossing an energy barrier of 1.06 eV. The decrease in total energy indicates that hydrogen tends to exist on the PuO2(111) surface in a hydrogen atom state. The research results lay the foundation for theoretically exploring the hydrogenation corrosion mechanism of the PuO2(111) surface, providing theoretical support for exploring the corrosion aging of plutonium oxide, predicting the material properties of plutonium oxide under extreme and special environments.

Controlling conjugated polymer morphology by precise oxygen position in single-ether side chains.

Recently, polar side chains have emerged as a functional tool to enhance conjugated polymer doping properties by improving the polymer miscibility with polar chemical dopants and facilitate solvated ion uptake. In this work, we design and investigate a novel family of side chains containing a single ether function, enabling the modulation of the oxygen atom position along the side chain. A meticulous investigation of this new polymer series by differential scanning calorimetry, fast scanning chip calorimetry and X-ray scattering shows that polymers bearing single-ether side chains can show high degree of crystallinity under proper conditions. Importantly, due to a gauche effect allowing the side chain to bend at the oxygen atom, the degree of crystallinity of polymers can be controlled by the position of the oxygen atom along the side chain. The further the oxygen atom is from the conjugated backbone, the more crystalline the polymer becomes. In addition, for all new polymers, high thermomechanical properties are demonstrated, leading to remarkable electrical conductivities and thermoelectric power factors in rub-aligned and sequentially doped thin films. This work confirms the potential of single-ether side chains to be used as polar solubilizing side chains for the design of a next generation of p- and n-type semiconducting polymers with increased affinity to polar dopants while maintaining high molecular order.

LDI mass spectrometry and quantum chemical calculations of four, five, and six atomic clusters of tantalum oxochloride anion-radicals

Quantum-chemical calculations of isomers of bulk closed “cage” structures of four, five and six atomic clusters of tantalum oxochloride anion-radicals, identified by LDI mass spectrometry in the gas phase, have been performed. The structure and relative thermodynamic stability of the isomers of clusters [Ta4OxCly]- (x = 6–9; y = 9, 7, 5,3), [Ta5OxCly]- (x = 8–12; y = 8, 6, 4, 2) and [Ta6OxCly]- (x = 12–15; y = 7, 5, 3, 1) of various configurations (tetrahedron, trigonal bipyrmide, tetragonal pyramid, trigonal prism, pentagonal pyramid and octahedron position of tantalum atoms) and different positions of oxygen and chlorine atoms have been studied. Some patterns of relative thermodynamic stability of isomers have been established. In the series of cluster radical anions of the same geometric configuration [TanOxCly]- (n = 4–6), the relative stability of geometric isomers depends on the ratio of the number of oxygen and chlorine atoms. For all anion-radicals [TanOxCly]- (n = 4–6) isomers having an anionic fragment with terminal oxygen and chlorine atoms (≡ТаOCl-) are energetically more favorable, than those with three of thes chlorine atoms (≡ TaCl3-). The average length of the Ta–Ta distances, in a series of cluster anions of tantalum oxochlorides [TanOxCly]- (n = 4–6) of the same geometric configuration, increases with a decrease in the number of oxygen atoms (an increase in the number of chlorine atoms). In the closed “cage” structures of the cluster anion radicals of tantalum oxochlorides, together with the oxygen, the chlorine can also act as a bridging atom, but the total binding energy of such isomer is higher.

Oxygen crystallographic positions in thin films by non-destructive resonant elastic X-ray scattering

Precisely locating oxygen atoms in nanosized systems is a real challenge. The traditional strategies used for bulk samples fail at probing samples with much less matter. Resonant elastic X-ray scattering (REXS) experiments in the X-ray absorption near-edge structure (XANES) domain have already proved their efficiency in probing transition metal cations in thin films, but it is not feasible to perform such experiments at the low-energy edges of lighter atoms – such as oxygen. In this study, the adequacy of using REXS in the extended X-ray absorption fine structure (EXAFS) domain, also known as extended diffraction absorption fine structure (EDAFS), to solve this issue is shown. The technique has been validated on a bulk FeV2O4 sample, through comparison with results obtained with conventional X-ray diffraction measurements. Subsequently, the positions of oxygen atoms in a thin film were unveiled by using the same strategy. The approach described in this study can henceforth be applied to solve the crystallographic structure of oxides, and will help in better understanding the properties and functionalities which are dictated by the positions of the oxygen atoms in functional nanosized materials.

Machine Learning for Shape Memory Graphene Nanoribbons and Applications in Biomedical Engineering.

Shape memory materials have been playing an important role in a wide range of bioengineering applications. At the same time, recent developments of graphene-based nanostructures, such as nanoribbons, have demonstrated that, due to the unique properties of graphene, they can manifest superior electronic, thermal, mechanical, and optical characteristics ideally suited for their potential usage for the next generation of diagnostic devices, drug delivery systems, and other biomedical applications. One of the most intriguing parts of these new developments lies in the fact that certain types of such graphene nanoribbons can exhibit shape memory effects. In this paper, we apply machine learning tools to build an interatomic potential from DFT calculations for highly ordered graphene oxide nanoribbons, a material that had demonstrated shape memory effects with a recovery strain up to 14.5% for 2D layers. The graphene oxide layer can shrink to a metastable phase with lower constant lattice through the application of an electric field, and returns to the initial phase through an external mechanical force. The deformation leads to an electronic rearrangement and induces magnetization around the oxygen atoms. DFT calculations show no magnetization for sufficiently narrow nanoribbons, while the machine learning model can predict the suppression of the metastable phase for the same narrower nanoribbons. We can improve the prediction accuracy by analyzing only the evolution of the metastable phase, where no magnetization is found according to DFT calculations. The model developed here allows also us to study the evolution of the phases for wider nanoribbons, that would be computationally inaccessible through a pure DFT approach. Moreover, we extend our analysis to realistic systems that include vacancies and boron or nitrogen impurities at the oxygen atomic positions. Finally, we provide a brief overview of the current and potential applications of the materials exhibiting shape memory effects in bioengineering and biomedical fields, focusing on data-driven approaches with machine learning interatomic potentials.

High valence states of Pd supported on ferroelectric BaTiO3 driven by electric polarization

At a metal–ferroelectric junction, it has been considered that the electric polarization of the ferroelectric material can affect the electronic structure of the neighboring metal. Here, we demonstrate that the valence state of Pd can be shifted to the unstable high value of 4+ by the electric field of electric polarization in ferroelectric BaTiO3. Study of the absorption fine structure of both hard and soft x rays revealed the existence of Pd4+ states on the surface of Pd oxide nanoparticles. The positions of Pd and oxygen atoms are shifted in opposite directions by the electric field due to the electric polarization of ferroelectric BaTiO3. The atomic displacement of Pd and O forms a zigzag structure, in which the coordination number of Pd atoms is changed from four to six, producing a quadrivalent state. This report presents experimental evidence that ferroelectric polarization can control the electronic states of neighboring metal atoms, and we suggest that using the ferroelectric support effect may produce a new type of catalyst.

Ether-Functionalized Pyrrolidinium-Based Room Temperature Ionic Liquids: Physicochemical Properties, Molecular Dynamics, and the Lithium Ion Coordination Environment.

The physicochemical properties of room temperature ionic liquids (RTILs) consisting of bis(trifluoromethanesulfonyl)amide (TFSA- ) combined with 1-hexyl-1-methylpyrrolidinium (Pyr1,6+ ), 1-(butoxymethyl)-1-methylpyrrolidinium (Pyr1,1O4+ ), 1-(4-methoxybutyl)-1-methyl pyrrolidinium (Pyr1,4O1+ ), and 1-((2-methoxyethoxy)methyl)-1-methylpyrrolidinium (Pyr1,1O2O1+ ) were investigated using both experimental and computational approaches. Pyr1,1O2O1 TFSA, which contains two ether oxygen atoms, showed the lowest viscosity, and the relationship between its physicochemical properties and the position and number of the ether oxygen atoms was discussed by a careful comparison with Pyr1,1O4 TFSA and Pyr1,4O1 TFSA. Ab initio calculations revealed the conformational flexibility of the side chain containing the ether oxygen atoms. In addition, molecular dynamics (MD) calculations suggested that the ion distributions have a significant impact on the transport properties. Furthermore, the coordination environments of the Li ions in the RTILs were evaluated using Raman spectroscopy, which was supported by MD calculations using 1000 ion pairs. The presented results will be valuable for the design of functionalized RTILs for various applications.

Synthesis and Properties of the Doubly Oxonium-Embedded Picenes as Electron-Deficient Polycyclic Aromatic Hydrocarbons

The doubly oxonium-embedded picenes have been synthesized for the first time. They have a rigid planar electron-deficient core and are stabilized by the pyrylium aromaticity. The doping positions of oxygen atoms influenced their electrochemical and optoelectronic properties because of the different charge distributions in the skeletons. The donor-acceptor-donor-type molecules baring electron-donating triphenylamine moieties exhibited intramolecular charge-transfer absorption at the visible regions, indicating the large impact of the substituents on their electronic properties.

Calculation and experimentation on the formation sequence of compounds at Al/Ti interface in pure Al antioxidant coatings

To investigate the precipitation order of intermetallic compounds at the Al/Ti interface, the enthalpy, entropy, Gibbs free energy, and heat capacity of Ti–Al compounds (including TiAl3, TiAl2, Ti3Al, and TiAl) were calculated using first-principles. In addition, the enthalpy of formation, entropy of formation and Gibbs free energy of formation of Ti–Al compounds were further calculated. By combining thermodynamics and diffusion dynamics, the effective free energy of formation model is proposed to predict the formation sequence of compounds at the Al/Ti interface. The results showed that the formation sequence of Ti–Al compounds followed TiAl3→TiAl2→TiAl→Ti3Al. Subsequently, the pure Al coating was prepared on the surface of pure titanium plate by arc spraying equipment and the specimens were heat-treated. The experimental results show that there was a transition zone composed of four layers of Ti–Al compounds at the interface. From the Al layer to the matrix direction, the four-layer compounds were TiAl3→TiAl2→TiAl→Ti3Al in turn, which was consistent with the calculated results. The EBSD analysis of the Al/Ti interface shows that the grain size of TiAl3 decreases gradually from the coating to the substrate direction when the heat treatment condition is 800 ℃/5 h, and the grain size and thickness of the Ti3Al layer are both larger than that of TiAl2 and TiAl layer. The Ti–Al phases at the interface presented random grain orientation. Finally, the calculation results of the preferred adsorption position of oxygen atoms on the TiAl3 (110)-Al surface show that the position of Al–Al bridge is the most preferred adsorption position of oxygen atoms and oxygen atoms are more inclined to form aluminum oxide by bonding with Al atoms.

Pump Frequency Resonances for Light-Induced Incipient Superconductivity in YBa2Cu3O6.5

Optical excitation in the cuprates has been shown to induce transient superconducting correlations above the thermodynamic transition temperature, $T_C$, as evidenced by the terahertz frequency optical properties in the non-equilibrium state. In YBa$_2$Cu$_3$O$_{6+x}$ this phenomenon has so far been associated with the nonlinear excitation of certain lattice modes and the creation of new crystal structures. In other compounds, like La$_{2-x}$Ba$_x$CuO$_4$, similar effects were reported also for excitation at near infrared frequencies, and were interpreted as a signature of the melting of competing orders. However, to date it has not been possible to systematically tune the pump frequency widely in any one compound, to comprehensively compare the frequency dependent photo-susceptibility for this phenomenon. Here, we make use of a newly developed optical parametric amplifier, which generates widely tunable high intensity femtosecond pulses, to excite YBa$_2$Cu$_3$O$_{6.5}$ throughout the entire optical spectrum (3 - 750 THz). In the far-infrared region (3 - 25 THz), signatures of non-equilibrium superconductivity are induced only for excitation of the 16.4 THz and 19.2 THz vibrational modes that drive $c$-axis apical oxygen atomic positions. For higher driving frequencies (25 - 750 THz), a second resonance is observed around the charge transfer band edge at ~350 THz. These observations highlight the importance of coupling to the electronic structure of the CuO$_2$ planes, either mediated by a phonon or by charge transfer.

The use of isoxazoline and isoxazole scaffolding in the design of novel thiourea and amide liquid-crystalline compounds.

A series of novel thiourea and amide liquid crystals containing 5-membered isoxazoline and isoxazole rings were synthetized and the liquid crystal properties studied. Thioureas were obtained using a condensation reaction of benzoyl chlorides, arylamines and ammonium thiocyanate. The amides, on the other hand, were the byproduct of a quantitative reaction which used potassium cyanate as the starting material. Thiourea and amide derivatives were predominantly SmA mesophase inductors. A nematic mesophase was observed only for thioureas and amides containing an isoxazole ring. Additionaly, the liquid crystal behavior was also dependent on the relative position of nitrogen and oxygen atoms on the 5-membered heterocycle.

Piperidinium-Based Ionic Liquids as an Electrolyte Solvent for Li-Ion Batteries: Effect of Number and Position of Oxygen Atom in Cation Side Chain on Electrolyte Property

In the pursuit of developing reliable Li-ion batteries with high performance and safety, the use of ionic liquids is one of the most promising approaches due to its high thermal stability. There is, however, the critical issue concerning the significantly low Li-ion diffusion in an electrolyte solution, which is directly linked to the degradation of their rapid charge−discharge properties. Ionic liquids with ether-substituted cation have generated much interest as electrolyte solvents for Li-ion batteries because the ether group functions to reduce the coordination number and increase ionic conductivity. In the present study, we synthesized six types of ionic liquids consisting of bis(trifluoromethanesulfonyl)amide (TFSA) anions and piperidinium-based cations in which the attached side chains are 1-((2-methoxyethoxy)methyl)-1-methylpiperidinium (PP1MEM), 1-butoxymethyl-1-methylpiperidinium (PP1BM), 1-methyl-(2-propoxyethyl)piperidinium (PP1PE), 1-(3-ethoxypropyl)-1-methylpiperidinium (PP1EP), 1-(4-methoxybutyl)-1-methylpiperidinium (PP1MB), and 1-hexyl-1-methylpiperidinium (PP16). It was found that the ionic liquid with PP1MEM cations with two oxygen atoms in the side chain exhibited the lowest solvation number of TFSA anions (1.56), whereas PP1BM (1.78), PP1PE (1.86), PP1EP (2.08), and PP1MB-TFSA (2.07) resulted in a larger number, as the oxygen atoms in the alkyl side chain are located far from the positively charged nitrogen atoms. PP1MEM-TFSA with small solvation numbers enhanced the ionic conductivity and thereby achieved high electrode performance.

The effects of the position of the ether oxygen atom in pyrrolidinium-based room temperature ionic liquids on their physicochemical properties.

Room temperature ionic liquids (RTILs) containing ether oxygen atoms have been investigated for a gamut of science and technology applications owing to their superior physicochemical properties. However, the effect of the position of the ether oxygen atom in the side chain on their physicochemical properties is not clearly understood. This study investigates, using both experimental and computational approaches, the effect of ether oxygen atoms on the physicochemical properties of RTILs consisting of bis(trifluoromethylsulfonyl)amide (TFSA-) with 1-methyl-1-propylpyrrolidinium (MPP+), 1-butyl-1-methylpyrrolidinium (BMP+), 1-methoxymethyl-1-methylpyrrolidinium (MOMMP+), 1-ethoxymethyl-1-methylpyrrolidinium (EOMMP+), and 1-methoxyethyl-1-methylpyrrolidinium (MOEMP+). The viscosity of the RTILs containing the ether oxygen atom was lower than that of the alkyl analogues. Moreover, the viscosity of EOMMPTFSA was lower than that of MOEMPTFSA, albeit EOMMPTFSA and MOEMPTFSA have the same molecular weight with ether oxygen atoms at different positions. Ab initio calculations reveal that the number of methylene groups between nitrogen and oxygen atoms in the cation structure profoundly impacts the local stable structure of the cation. Furthermore, we discussed the relationship between the transport properties and the spatial distribution of ions obtained by MD simulations. This result will be valuable in the design of functionalized RTILs, via the judicious tuning of the conformational flexibility of ether oxygen atoms in related ionic liquids.

Correction: The effects of the position of the ether oxygen atom in pyrrolidinium-based room temperature ionic liquids on their physicochemical properties.

Correction for 'The effects of the position of the ether oxygen atom in pyrrolidinium-based room temperature ionic liquids on their physicochemical properties' by Kazuki Yoshii et al., Phys. Chem. Chem. Phys., 2020, DOI: .

Ядерное квадрупольное взаимодействие и эффективные заряды атомов в кристаллах YBa2Cu3O7_x и La2_xSrxCuO4

Проведено сопоставление параметров эмиссионных мессбауэровских спектров на изотопах 57Co(57mFe), 67Cu(67Zn), 67Ga(67Zn), 155Eu(155Gd) и параметров ядерного магнитного резонанса на изотопах 17O, 137Ba с расчетными параметрами решеточного тензора градиента электрического поля для всех узлов кристаллических решеток высокотемпературных сверхпроводников на основе металлооксидов меди YBa2Cu3O7 и La2-xSrxCuO4. Согласие экспериментальных и расчетных параметров тензора градиента электрического поля может быть получено только для моделей, когда дырка, возникающая за счет нестехиометричности соединения YBa2Cu3O7 или аливалентного замещения La3+ на Sr2+ в соединениях La2-xSrxCuO4, находится преимущественно в подрешетке цепочечного (в YBa2Cu3O7) или плоскостного (в La2-xSrxCuO4) кислорода. Подтверждение предложенной модели пространственного распределения электронных дефектов в решетках La2-xSrxCuO4 (x = 0.1 - 1.0) было получено путем сравнения расчетных зависимостей отношения главных компонент тензоров градиента электрического поля в узлах лантана и меди с отношением постоянных квадрупольного взаимодействия в этих узлах для зондов 57mFe3+, 67Zn2+ и 155Ga3+. Наблюдаемые зависимости могут быть количественно объяснены, если дырка локализуется преимущественно в позициях атомов планарного кислорода. С использованием этих моделей определены коэффициенты Штернхеймера для зондов 67Zn2+, 137Ba2+ и 17O2-.

A commensurately modulated crystal structure and the physical properties of a novel polymorph of the caesium manganese phosphate CsMnPO4.

A novel modification of the CsMnPO4 β-phase was achieved by hydrothermal synthesis at 553 K. The compound crystallizes in the monoclinic system with the basic unit-cell parameters a = 11.0699 (4), b = 11.0819 (6), c = 9.1106 (3) Å, γ = 119.480 (5)o; the modulation vectors are q1 = 0.4a* and q2 = 0.4b*. The structure was determined based on single-crystal X-ray diffraction data obtained from a pseudo-merohedral twin using a superspace approach in the (3 + 2)D symmetry group P11a(a1,b1,0)0(a2,b2,0)0 and refined to R = 0.083 for 10 266 reflections with I > 3σ(I). It is considered as a low-temperature polymorph of CsMnPO4 with the same UUUDDD-type layer topology built by MnO4 and PO4 tetrahedra, and stacked in a framework in the same manner as β-tridymite. Large open channels parallel to the [110] and [001] directions incorporate Cs atoms. All Cs atoms are distributed along the asuper = 55.35 (1) and bsuper = 55.41 (1) axes of the large unit cell with pseudo periods of asuper/5 and bsuper/5 which are broken mainly by the positions of oxygen atoms (orientation of Mn- and P-centered tetrahedra). The β-phase is discussed as a member of the morphotropic series of manganese phosphates with large cations of AMnPO4, where A = Cs, Rb, K and Ag. The title compound is an antiferromagnet with the Neel temperature TN = 4.5 K.