Molecular Moment Research Articles

Crystal structures, DFT calculations and Hirshfeld surface analysis of two (E)-3-(aryl)-1-(naphthalen-1-yl)prop-2-en-1-one chalcone derivatives, potential Mycobacterium tuberculosis Enoyl ACP reductase (InhA) inhibitors and optical materials: conformational differences within the prop-2-en-1-one unit

A combined structural and computational study has been conducted on two chalcone compounds, namely (E)-3-(4-bromophenyl)-1-(4,8-dimethoxynaphthalen-1-yl)prop-2-en-1-one (1), and (E)-3-(3,4-dichlorophenyl)-1-(4,8-dimethoxynaphthalen-1-yl)prop-2-en-1-one (2). These compounds are members of a series of compounds identified from a molecular modelling study as potentially active Mycobacterium tuberculosis Enoyl ACP reductase (InhA) inhibitors. In addition, the computational study indicated that the compounds have potential as optical materials.The combined study revealed that both molecules in the solid state displayed similar overall molecular conformations between a ‘‘T’’ and a ‘‘Y’’ shape, but with different arrangements in the bridging prop-2-en-1-one unit: an anti-periplanar in 1 and a syn-periplanar in 2. The experimental and calculated bond lengths and angles for anti-periplanar1 and syn-periplanar2 were generally in good agreement.Theoretical calculations at the B3LYP/DGTZVP level in the gas phase, DMSO and water media indicated that for both compounds, the syn-periplanar form was the energy local minimum while the anti-periplanar form was the energy global minimum. However, the energy differences are very small, with slight variations when using the different basis sets (0.80 and 0.84 kcal/mol using the B3LYP/DGTVP theory level in gas phase, 0.28 and 0.32 in DMSO and 0.27 and 0.31 kcal/mol in water). The differences in the solid state arrangements within the bridging prop-2-en-1-one unit in 1 and 2 arise from variations in the intermolecular interactions, with halogen bonds being considered to be an important factor in stabilizing a syn-periplanar arrangement in compound 2. PLATON and Hirshfeld surface analyses confirmed the important intermolecular interactions in 1 and 2.Calculations were also carried out on the electronic and vibrational spectra, dipole moments and charge distributions of 1 and 2. The HOMO was located in the dimethoxynaphthalenyl region of the molecule with mild donor character, while the LUMO was located in the propenyl and phenyl regions of each molecule. The energy gaps between these orbitals are 3.35 eV for 1 3.25 eV for 2. The delocalization present in compounds 1 and 2 facilitates the HOMO-LUMO charge transfer process.The total electronic molecular dipolar moments (μTotal) were calculated to be 4.1511 and 5.9316 D for 1 and 2, respectively. The values of μTotal found for 1 and 2 are both larger than reported values for similar compounds, indicating that the compounds studied here should exhibit a good non-linear optical response.

Anharmonic Thermal Motion Modelling in the Experimental XRD Charge Density Determination of 1-Methyluracil at T = 23 K.

The experimental electron density distribution (EDD) of 1-methyluracil (1-MUR) was obtained by single crystal X-ray diffraction (XRD) experiments at 23 K. Four different structural models fitting an extensive set of XRD data to a resolution of (sinθ/λ)max = 1.143 Å−1 are compared. Two of the models include anharmonic temperature factors, whose inclusion is supported by the Hamilton test at a 99.95% level of confidence. Positive Fourier residuals up to 0.5 eÅ–3 in magnitude were found close to the methyl group and in the region of hydrogen bonds. Residual density analysis (RDA) and molecular dynamics simulations in the solid-state demonstrate that these residuals can be likely attributed to unresolved disorder, possibly dynamical and long–range in nature. Atomic volumes and charges, molecular moments up to hexadecapoles, as well as maps of the molecular electrostatic potential were obtained from distributed multipole analysis of the EDD. The derived electrostatic properties neither depend on the details of the multipole model, nor are significantly affected by the explicit inclusion of anharmonicity in the least–squares model. The distribution of atomic charges in 1-MUR is not affected by the crystal environment in a significant way. The quality of experimental findings is discussed in light of in-crystal and gas-phase quantum simulations.

Design of Mn–Mn distance for tunable spontaneous exchange bias in Heusler alloys

To accelerate the discovery of spontaneous exchange bias (SEB) materials and optimize its performance, reasonable design scheme is needed. Taking advantage of the extremely sensitive dependence of SEB on the value of molecular magnetic moments in the Mn-rich Heusler alloys, a design scheme of the Mn–Mn distance for SEB is proposed to tune the molecular magnetic moment in the Ni-rich Heusler alloys. Here, it is found that the Mn–Mn distance can be controlled in the Ni2Mn1.4In0.6-xAlx system. The experimental results show that SEB is achieved in Ni2Mn1.4In0.6-xAlx (x = 0.24–0.56), and the SEB field is indeed dominated by the Mn–Mn distance. Therefore, the Mn–Mn distance can tune the molecular magnetic moment, and then tune SEB. Our findings demonstrate that the design of the Mn–Mn distance is an effective method to tune SEB. This opens up a new approach to the development of SEB materials.

Giant magnetoresistance due to orbital-symmetry mismatch in transition metal benzene sandwich molecules

Achieving large magnetoresistance (MR) effects in atomic-scale junctions is of great importance in the field of molecular spintronics. In this work, using ab initio quantum transport calculations, we report on the spin transport properties of molecular junctions made of single transition metal benzene sandwich molecules $(\mathrm{TM}{\mathrm{Bz}}_{2})$ bridged by ferromagnetic electrodes. We find that relative magnetic orientations of two electrodes and the molecule can dramatically affect low-bias transport properties of the junction. While the $\mathrm{TM}{\mathrm{Bz}}_{2}$ are insulating in the gas phase, their corresponding molecular junctions bridged between the two electrodes are half-metallic minority-spin conductors (i.e., almost 100% spin polarization) and display very large MR. More interestingly, even larger molecular MR, corresponding to a reversal of molecular spin moment, are found due to the spin-valve behavior of the molecule controlled by the magnetic impurity. Such a particular performance is attributed to strong spin-selective hybridization of electronic states at the molecule/metal interface due to orbital-symmetry mismatch between the electrode's and molecular states. We also discuss the importance of the shape of electrodes on spin transport efficiency.

Too big, too small, or just right? A benchmark assessment of density functional theory for predicting the spatial extent of the electron density of small chemical systems.

Multipole moments are the first-order responses of the energy to spatial derivatives of the electric field strength. The quality of density functional theory prediction of molecular multipole moments thus characterizes errors in modeling the electron density itself, as well as the performance in describing molecules interacting with external electric fields. However, only the lowest non-zero moment is translationally invariant, making the higher-order moments origin-dependent. Therefore, instead of using the 3 × 3 quadrupole moment matrix, we utilize the translationally invariant 3 × 3 matrix of second cumulants (or spatial variances) of the electron density as the quantity of interest (denoted by K). The principal components of K are the square of the spatial extent of the electron density along each axis. A benchmark dataset of the principal components of K for 100 small molecules at the coupled cluster singles and doubles with perturbative triples at the complete basis set limit is developed, resulting in 213 independent K components. The performance of 47 popular and recent density functionals is assessed against this Var213 dataset. Several functionals, especially double hybrids, and also SCAN and SCAN0 predict reliable second cumulants, although some modern, empirically parameterized functionals yield more disappointing performance. The H, Li, and Be atoms, in particular, are challenging for nearly all methods, indicating that future functional development could benefit from the inclusion of their density information in training or testing protocols.

Ultra-cold long-range Rydberg-ground molecules

<sec> Ultra-cold long-range Rydberg-ground molecule consisting of a Rydberg atom and one or more ground-state atoms is formed by low-energy scattering between the Rydberg electron and ground-state atoms located inside the Rydberg electron’s wave function. The low-energy scattering interaction, initially investigated by Fermi and Omont, has been predicted to lead to molecular binding in a novel type of Rydberg molecules, including the trilobite and butterfly molecules. Their unconventional binding mechanism, which is unlike covalent, or ionic, or van der Waals bonds, results in loosely bound molecules with bond lengths on the order of thousands of Bohr radius. This kind of molecule with large size and huge permanent electric dipole moment is a good candidate for realizing the certain strongly correlated many-body gases and for quantum information processing, as well as for dipolar quantum gases and spin systems with long-range interactions. Consequently, these molecules have received considerable attention in recent years.</sec><sec>In this paper, we review the recent theoretical and experimental investigations of ultra-cold long-range Rydberg-ground molecules, including the scattering interaction between the Rydberg electron and ground-state atom and the resulting adiabatic potential curves, experimental observations of photo-associated Rydberg-ground molecules spectra, as well as the measurements of permanent electric dipole moment. Ultra-cold long-range Rydberg-ground molecules are prepared by photoassociation in a high-density cold atom sample. Therefore, the Rydberg electron can bind several ground-state atoms to form a polyatomic Rydberg-ground molecule. The permanent molecular electric-dipole moments are revealed by spectral line broadening in the electric fields. The latest research pointed out that the permanent electric dipole moments of the Cs <i>n</i>D<sub><i>J</i></sub> -type Rydberg-ground molecules are negative, which is different from the previous reports (the electric dipole moments are positive). The negative sign reflects a deficiency of Rydberg-electron density near the ground-state perturber, which is caused by electronic configuration mixing. </sec>

Modeling Adsorption in Silica Pores via Minkowski Functionals and Molecular Electrostatic Moments

Capillary condensation phenomena are important in various technological and environmental processes. Using molecular simulations, we study the confined phase behavior of fluids relevant to carbon sequestration and shale gas production. As a first step toward translating information from the molecular to the pore scale, we express the thermodynamic potential and excess adsorption of methane, nitrogen, carbon dioxide, and water in terms of the pore’s geometric properties via Minkowski functionals. This mathematical reconstruction agrees very well with molecular simulations data. Our results show that the fluid molecular electrostatic moments are positively correlated with the number of adsorption layers in the pore. Moreover, stronger electrostatic moments lead to adsorption at lower pressures. These findings can be applied to improve pore-scale thermodynamic and transport models.

DoNOF: An open-source implementation of natural-orbital-functional-based methods for quantum chemistry

The natural orbital functional theory (NOFT) has emerged as an alternative formalism to both density functional (DF) and wavefunction methods. In NOFT, the electronic structure is described in terms of the natural orbitals (NOs) and their occupation numbers (ONs). The approximate NOFs have proven to be more accurate than those of the density for systems with a significant multiconfigurational character, on one side, and scale better with the number of basis functions than correlated wavefunction methods, on the other side. A challenging task in NOFT is to efficiently perform orbital optimization. In this article we present DoNOF, our open source implementation based on diagonalizations that allows to obtain the resulting orbitals automatically orthogonal. The one-particle reduced-density matrix (1RDM) of the ensemble of pure-spin states provides the proper description of spin multiplets. The capabilities of the code are tested on the water molecule, namely, geometry optimization, natural and canonical representations of molecular orbitals, ionization potential, and electric moments. In DoNOF, the electron-pair-based NOFs developed in our group PNOF5, PNOF7 and PNOF7s are implemented. These JKL-only NOFs take into account most non-dynamic effects plus intrapair-dynamic electron correlation, but lack a significant part of interpair-dynamic correlation. Correlation corrections are estimated by the single-reference NOF-MP2 method that simultaneously calculates static and dynamic electron correlations taking as a reference the Slater determinant formed with the NOs of a previous PNOF calculation. The NOF-MP2 method is used to analyze the potential energy surface (PES) and the binding energy for the symmetric dissociation of the water molecule, and compare it with accurate wavefunction-based methods.

Cesium nDJ+6S1/2 Rydberg molecules and their permanent electric dipole moments

Cs$_2$ Rydberg-ground molecules consisting of a Rydberg, $nD_{J}$ (33 $\leq$ $n$ $\leq$ 39), and a ground state atom, 6$S_{1/2} (F=$3 or 4$)$, are investigated by photo-association spectroscopy in a cold atomic gas. We observe vibrational spectra that correspond to triplet $^T\Sigma$ and mixed $^{S,T}\Sigma$ molecular states. We establish scaling laws for the energies of the lowest vibrational states vs principal quantum number and obtain zero-energy singlet and triplet $s$-wave scattering lengths from experimental data and a Fermi model. Line broadening in electric fields reveals the permanent molecular electric-dipole moments; measured values agree well with calculations. We discuss the negative polarity of the dipole moments, which differs from previously reported cases.

Fast analytical evaluation of intermolecular electrostatic interaction energies using the pseudoatom representation of the electron density. III. Application to crystal structures via the Ewald and direct summation methods

The previously reported exact potential and multipole moment (EP/MM) method for fast and accurate evaluation of the intermolecular electrostatic interaction energies using the pseudoatom representation of the electron density [Volkov, Koritsanszky & Coppens (2004). Chem. Phys. Lett. 391, 170-175; Nguyen, Kisiel & Volkov (2018). Acta Cryst. A74, 524-536; Nguyen & Volkov (2019). Acta Cryst. A75, 448-464] is extended to the calculation of electrostatic interaction energies in molecular crystals using two newly developed implementations: (i) the Ewald summation (ES), which includes interactions up to the hexadecapolar level and the EP correction to account for short-range electron-density penetration effects, and (ii) the enhanced EP/MM-based direct summation (DS), which at sufficiently large intermolecular separations replaces the atomic multipole moment approximation to the electrostatic energy with that based on the molecular multipole moments. As in the previous study [Nguyen, Kisiel & Volkov (2018). Acta Cryst. A74, 524-536], the EP electron repulsion integral is evaluated analytically using the Löwdin α-function approach. The resulting techniques, incorporated in the XDPROP module of the software package XD2016, have been tested on several small-molecule crystal systems (benzene, L-dopa, paracetamol, amino acids etc.) and the crystal structure of a 181-atom decapeptide molecule (Z = 4) using electron densities constructed via the University at Buffalo Aspherical Pseudoatom Databank [Volkov, Li, Koritsanszky & Coppens (2004). J. Phys. Chem. A, 108, 4283-4300]. Using a 2015 2.8 GHz Intel Xeon E3-1505M v5 computer processor, a 64-bit implementation of the Löwdin α-function and one of the higher optimization levels in the GNU Fortran compiler, the ES method evaluates the electrostatic interaction energy with a numerical precision of at least 10-5 kJ mol-1 in under 6 s for any of the tested small-molecule crystal structures, and in 48.5 s for the decapeptide structure. The DS approach is competitive in terms of precision and speed with the ES technique only for crystal structures of small molecules that do not carry a large molecular dipole moment. The electron-density penetration effects, correctly accounted for by the two described methods, contribute 28-64% to the total electrostatic interaction energy in the examined systems, and thus cannot be neglected.

Anomalous photoluminescence quenching in DIP/MoS2 van der Waals heterostructure: Strong charge transfer and a modified interface

Due to the fascinating optoelectronic properties of two-dimensional (2D) transition metal dichalcogenides (TMDs) and the flexible nature, vast library, and easy fabrication process of organic molecules, the combination of 2D TMD materials and organic molecules have been gaining enormous attention in recent years. The organic semiconductors can enhance the optoelectronic and improved transport properties by interfacing with atomically thin TMDs through vdW interaction. Here, we investigate the photoluminescence (PL) properties of type-II heterostructure made of monolayer molybdenum disulfide (ML MoS2) and a non-planar Diindenoperylene(DIP) molecules. A drastic quenching of PL intensity nearly 300% is observed with slightly redshift in DIP/MoS2as compared to the PL of isolated MoS2. The observed quenching behavior in DIP/MoS2heterostructure can be explained by the appeared ‘trap – like’ states in density of states (DOS), and suppression of exciton to trion ratio due to electron transfer from the lowest unoccupied molecular orbital (LUMO) level of DIP to the conduction band minima (CBM) of MoS2. Furthermore, the redshift in the PL of heterostructure could be due to weak coupling strength which is ~8 times smaller than that of the energy of A-exciton resonance of individual layers and dielectric screening effect induced by the non-planar DIP based organic layer. The expected strong interaction between the DIP molecule and MoS2 layer due to the permanent dipole moments (significant molecular quadruple moment 8.25D) of DIP molecules is another reason, which may slightly reduce the bandgap and results in red-shift of PL. We observed Raman (A1g phonon mode) is blue-shifted, which is supposed to stiffening due to the non-planar DIP molecule onto ML MoS2. The strong PL quenching behavior of DIP/MoS2heterostructure can be a potential candidate for tailoring the optoelectronic properties of TMDs that may demonstrate for light-harvesting and canserve as the next generation TMD/organic-based photovoltaic applications.

GGA and GGA Plus U Study of Half-Metallic Quaternary Heusler Compound CoCrScSn

The structural, mechanical, electronic, magnetic, and half-metallic properties of quaternary Heusler compound CoCrScSn are studied using the GGA and GGA+U method based on first-principles calculations. It is found that Type-I structure of CoCrScSn compound is the most stable, and its ground state is ferromagnetic. At the equilibrium lattice constant, the electronic structures obtained by GGA and GGA+U methods indicate that CoCrScSn compound have typical half-metal character. The results of elastic constants and half-metallic robustness show that the mechanical stability and half-metallicity of CoCrScSn can be well maintained in the range of 6.2 to 6.9 Å under GGA and 5.7 to 6.4 Å under GGA+U, respectively. When CoCrScSn compound exhibits half-metallic properties, the total magnetic moment per molecular unit is 4.0 μB, which is in good agreement with the Slater-Pauling rule, and Cr atoms are the main source of molecular magnetic moment. All the aforementioned results indicate that quaternary Heusler compound CoCrScSn would be an ideal candidate in spintronics.

Multiscale Coarse-Grained Approach to Investigate Self-Association of Antibodies

Self-association of therapeutic monoclonal antibodies (mabs) are thought to modulate the undesirably high viscosity observed in their concentrated solutions. Computational prediction of such a self-association behavior is advantageous early during mab drug candidate selection when material availability is limited. Here, we present a coarse-grained (CG) simulation method that enables microsecond molecular dynamics simulations of full-length antibodies at high concentrations. The proposed approach differs from others in two ways: first, charges are assigned to CG beads in an effort to reproduce molecular multipole moments and charge asymmetry of full-length antibodies instead of only localized charges. This leads to great improvements in the agreement between CG and all-atom electrostatic fields. Second, the distinctive hydrophobic character of each antibody is incorporated through empirical adjustments to the short-range van der Waals terms dictated by cosolvent all-atom molecular dynamics simulations of antibody variable regions. CG simulations performed on a set of 15 different mabs reveal that diffusion coefficients in crowded environments are markedly impacted by intermolecular interactions. Diffusion coefficients computed from the simulations are in correlation with experimentally measured observables, including viscosities at a high concentration. Further, we show that the evaluation of electrostatic and hydrophobic characters of the mabs is useful in predicting the nonuniform effect of salt on the viscosity of mab solutions. This CG modeling approach is particularly applicable as a material-free screening tool for selecting antibody candidates with desirable viscosity properties.

Calculation of Quantum Chemical Values of Corrosion Inhibitors Molecules by Heterocyclic Compounds

Theoretical concepts of inhibition mechanism in metal corrosion and forecasting of protective properties of substances are connected with experimental (electrochemical, adsorption, mechano-chemical) research. Inhibition mechanism may be fully demonstrated by comparing experimental research data with results of calculating quantum-chemical values of the proposed corrosion inhibitors molecules. The latter therewith enable to detect those physico-chemical characteristics that directly demonstrate protective properties of the inhibitor. Molecular moment, number of atoms in molecule and number of electrons in outer molecular orbitals are found to have maximum affect on the protection level. Application of petrochemical products including semi-finished products and petrochemical wastes for making new highly efficient and relatively inexpensive corrosion inhibitors is shown to be promising. Calculation results of quantum chemical values of corrosion inhibitors molecules by heterocyclic compounds may be used in learning corrosion inhibition mechanism by the compounds studied.

On-Surface Atom-by-Atom-Assembled Aluminum Binuclear Tetrabenzophenazine Organometallic Magnetic Complex.

The Kondo effect results from the interactions of the conduction electrons in a metal bulk with localized magnetic impurities. While adsorbed atop a metallic surface, the on-surface nanoscale version of this effect is observed when a single magnetic atom or a single magnetic molecule (SMM) is interacting with the conduction electrons. SMMs are commonly organometallic complexes incorporating transition-metal atoms in different oxidation states. We demonstrate how a single nonmagnetic neutral tetrabenzo[a,c,j,h]phenazine molecule can be on-surface-coordinated with exactly two aluminum metal atoms (between Al(I) and Al(II) oxidation state on the Au(111) surface) by low-temperature scanning tunneling microscope (LT-STM) single-atom manipulation. It results in a Kondo measurable localized molecular magnetic moment. This opens a new way to design SMM complexes without the need for heavy transition-metal atoms and complex ligands to stabilize the molecular coordination sphere.

Thermal response properties and surface insulation failure mechanism of epoxy resin under arc ablation

Arc ablation during the operation of HVDC circuit breakers can cause irreversible damage to the epoxy resin (EP) insulation pull rod. This is one of the critical factors that affect the reliability and lifetime of a HVDC circuit breaker. In this work, we built an arc ablation experimental platform and studied the thermal response properties of EP insulation under arc ablation. The surface charge evolution characteristics and the dielectric properties were analyzed to reveal the underlying surface insulation failure mechanism of EP after arc ablation. The results indicate that arc ablation can cause severe carbonization to EP insulation. With increasing arc duration, the EP gradually transforms into carbide and pore products. Arc ablation can decrease the molecular moment orientation polarizability and the relative dielectric constant of EP insulation, and thereby increasing the current density formed by Schottky injection. Therefore, when the external electric field is applied, the charge on EP insulation surface migrates from high voltage electrode to the ablating area, causing the regional accumulation of surface charge and the formation of local failure area. This can decrease the surface electrical performance of EP insulation and lead to insulation failure finally.

First-Principles Calculations of the Structural, Magnetic, and Electronic Properties of $$\hbox {Fe}_{2}\hbox {MgB}$$ Full-Heusler Alloy

The structural, magnetic, and electronic properties of a new $$\hbox {Fe}_{2}\hbox {MgB}$$ full-Heusler alloy were calculated using a first-principles approach based on density functional theory. The conventional $$\hbox {Cu}_{2}\hbox {MnAl}$$ -type and inverse $$\hbox {Hg}_{2}\hbox {CuTi}$$ -type structures in nonmagnetic and ferromagnetic states were considered for the full-Heusler alloy. The ferromagnetic $$\hbox {Hg}_{2}\hbox {CuTi}$$ -type structure was found to be the most energetically favourable. $$\hbox {Fe}_{2}\hbox {MgB}$$ with ferromagnetic structure has a molecular magnetic moment of 3.000 $$\mu _{B}$$ at the equilibrium lattice constant of 5.562 A. The molecular magnetic moment originates from the alloy’s two Fe atoms and obeys the Slater–Pauling rule. The majority-spin channels are metallic, whereas the minority-spin electrons exhibited a semiconducting behaviour with an indirect narrow gap of 0.179 eV in the equilibrium state. The ferromagnetic $$\hbox {Hg}_{2}\hbox {CuTi}$$ -type $$\hbox {Fe}_{2}\hbox {MgB}$$ is proven to be a potential half-metallic material suitable for use in spintronics.

Analysis of the Moment Method and the Discrete Velocity Method in Modeling Non-Equilibrium Rarefied Gas Flows: A Comparative Study

In the present study, the performance of the moment method, in terms of accuracy and computational efficiency, was evaluated at both the macro- and microscopic levels. Three different types of non-equilibrium gas flows, including the force-driven Poiseuille flow, lid-driven and thermally induced cavity flows, were simulated in the slip and transition regimes. Choosing the flow fields obtained from the Boltzmann model equation as the benchmark, the accuracy and validation of Navier–Stokes–Fourier (NSF), regularized 13 (R13) and regularized 26 (R26) equations were explored at the macroscopic level. Meanwhile, we reconstructed the velocity distribution functions (VDFs) using the Hermite polynomials with different-order of molecular velocity moments, and compared them with the Boltzmann solutions at the microscopic level. Moreover, we developed a kinetic criterion to indirectly assess the errors of the reconstructed VDFs. The results have shown that the R13 and R26 moment methods can be faithfully used for non-equilibrium rarefied gas flows in the slip and transition regimes. However, as indicated from the thermally induced case, all of the reconstructed VDFs are still very close to the equilibrium state, and none of them can reproduce the accurate VDF profile when the Knudsen number is above 0.5.

Effect of Strain on the Elastic, Electronic, and Magnetic Properties of Fluoro-Pervskite RbMnF3 and RbFeF3

The elastic constants, electronic structure, and magnetic properties of rubidium-based fluoro-pervskite ferromagnetic semiconductor RbMnF3 and ferromagnetic half-metal RbFeF3 under strain were studied by first-principle methods. The calculation of elastic constants and mechanical parameters shows that both RbMnF3 and RbFeF3 have very stable mechanical properties in the strain range studied. In the strain range of − 6.0 to 10.0%, the ferromagnetic semiconductor characteristics of RbMnF3 can be maintained, and the semiconductor band gap can be increased from 1.49 eV at equilibrium to a maximum value of 1.80 eV under strain. The half-metallicity of RbFeF3 can also be preserved in the strain range of − 8.0 to 10.0%, and the half-metallic gap can reach up to 1.19 eV in this strain range. When RbMnF3 and RbFeF3 are ferromagnetic semiconductor and ferromagnetic half-metal, respectively, their molecular magnetic moments are integer values, and transition metal atoms are the most important contributors to total magnetic moment. Strong correlation correction does not change the physical properties of RbMnF3 and RbFeF3 in equilibrium state.

Full Dimensional Potential Energy Function and Calculation of State-Specific Properties of the CO+N2 Inelastic Processes Within an Open Molecular Science Cloud Perspective.

A full dimensional Potential Energy Surface (PES) of the CO + N2 system has been generated by extending an approach already reported in the literature and applied to N2-N2 (Cappelletti et al., 2008), CO2-CO2 (Bartolomei et al., 2012), and CO2-N2 (Lombardi et al., 2016b) systems. The generation procedure leverages at the same time experimental measurements and high-level ab initio electronic structure calculations. The procedure adopts an analytic formulation of the PES accounting for the dependence of the electrostatic and non-electrostatic components of the intermolecular interaction on the deformation of the monomers. In particular, the CO and N2 molecular multipole moments and electronic polarizabilities, the basic physical properties controlling the behavior at intermediate and long-range distances of the interaction components, were made to depend on relevant internal coordinates. The formulated PES exhibits substantial advantages when used for structural and dynamical calculations. This makes it also well suited for reuse in Open Molecular Science Cloud services.