Designing a molecule with desired properties is one of the biggest challenges in drug development, as it requires optimization of chemical compound structures with respect to many complex properties. To augment the compound design process we introduce Mol-CycleGAN -a CycleGAN-based model that generates optimized compounds with high structural similarity to the original ones. Namely, given a molecule our model generates a structurally similar one with an optimized value of the considered property. We evaluate the performance of the model on selected optimization objectives related to structural properties (presence of halogen groups, number of aromatic rings) and to a physicochemical property (penalized logP).In the task of optimization of penalized logP of drug-like molecules our model significantly outperforms previous results.

A systematic diagrammatic expansion for Gutzwiller-wave functions (DE-GWF) proposed very recently is used for the description of superconducting (SC) ground state in the two-dimensional square-lattice t-J model with the hopping electron amplitudes t (and t ′ ) between nearest (and nextnearest) neighbors. On the example of the SC state analysis we provide a detailed comparison of the method results with other approaches. Namely: (i) the truncated DE-GWF method reproduces the variational Monte Carlo (VMC) results; (ii) in the lowest (zeroth) order of the expansion the method can reproduce the analytical results of the standard Gutzwiller approximation (GA), as well as of the recently proposed "grand-canonical Gutzwiller approximation" (GCGA). We obtain important features of the SC state. First, the SC gap at the Fermi surface resembles a d x 2 −y 2wave only for optimally-and overdoped system, being diminished in the antinodal regions for the underdoped case in a qualitative agreement with experiment. Corrections to the gap structure are shown to arise from the longer range of the real-space pairing. Second, the nodal Fermi velocity is almost constant as a function of doping and agrees semi-quantitatively with experimental results.Third, we compare the doping dependence of the gap magnitude with experimental data. Fourth, we analyze the k-space properties of the model: Fermi surface topology and effective dispersion.The DE-GWF method opens up new perspectives for studying strongly-correlated systems, as: (i) it works in the thermodynamic limit, (ii) is comparable in accuracy to VMC, and (iii) has numerical complexity comparable to GA (i.e., it provides the results much faster than the VMC approach).of the model used in the literature. Unless stated otherwise, the system's spin-isotropy

Selected universal experimental properties of high temperature superconducting (HTS) cuprates have been singled out in the last decade. One of the pivotal challenges in this field is the designation of a consistent interpretation framework within which we can describe quantitatively the universal features of those systems. Here we analyze in a detailed manner the principal experimental data and compare them quantitatively with the approach based on a single band of strongly correlated electrons supplemented with strong antiferromagnetic (super)exchange interaction (the so-called t-J-U model). The model rationale is provided by estimating its macroscopic parameters on the basis of the 3-band approach for the Cu-O plane. We use our original full Gutzwiller-wave-function solution by going beyond the renormalized mean field theory (RMFT) in a systematic manner. Our approach reproduces very well the observed hole doping (δ) dependence of the kinetic-energy gain in the superconducting phase, one of the principal non-Bardeen-Cooper-Schrieffer features of the cuprates. The calculated Fermi velocity in the nodal direction is practically δ-independent and its universal value agrees very well with that determined experimentally. Also, a weak doping dependence of the Fermi wave-vector leads to an almost constant value of the effective mass in a pure superconducting phase which is both observed in the experiment and reproduced within our approach. An assessment of the currently used models is carried out and the results of the canonical RMFT as a zeroth-order solution are provided for comparison to illustrate the necessity of introduced higher order contributions.

A systematic diagrammatic expansion for Gutzwiller wavefunctions (DE-GWFs) proposed very recently is used for the description of the superconducting (SC) ground state in the two-dimensional square-lattice t-J model with the hopping electron amplitudes t (and ′ t ) between nearest (and next-nearest) neighbors. For the example of the SC state analysis we provide a detailed comparison of the methodʼs results with those of other approaches. Namely, (i) the truncated DE-GWF method reproduces the variational Monte Carlo (VMC) results and (ii) in the lowest (zeroth) order of the expansion the method can reproduce the analytical results of the standard Gutzwiller approximation (GA), as well as of the recently proposed 'grand-canonical Gutzwiller approximation' (called either GCGA or SGA). We obtain important features of the SC state. First, the SC gap at the Fermi surface resembles a − d x y 2 2 wave only for optimally and overdoped systems, being diminished in the antinodal regions for the underdoped case in a qualitative agreement with experiment. Corrections to the gap structure are shown to arise from the longer range of the real-space pairing. Second, the nodal Fermi velocity is almost constant as a function of doping and agrees semi-quantitatively with experimental results. Third, we compare the Content from this work may be used under the terms of the Creative Commons Attribution 3.0 licence. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI.doping dependence of the gap magnitude with experimental data. Fourth, we analyze the k-space properties of the model: Fermi surface topology and effective dispersion. The DE-GWF method opens up new perspectives for studying strongly correlated systems, as it (i) works in the thermodynamic limit, (ii) is comparable in accuracy to VMC, and (iii) has numerical complexity comparable to that of the GA (i.e., it provides the results much faster than the VMC approach). Keywords: t-J model, high-temperature superconductivity, Gutzwiller wave function, unconventional superconductivity, variational Monte-Carlo method New J. Phys. 16 (2014) 073018 J Kaczmarczyk et al c n c n 1 , 1 i i i i , , representations. New J. Phys. 16 (2014) 073018 J Kaczmarczyk et al New J. Phys. 16 (2014) 073018 J Kaczmarczyk et al New J. Phys. 16 (2014) 073018 J Kaczmarczyk et al 6 New J. Phys. 16 (2014) 073018 J Kaczmarczyk et al 9 , eff , and Δ i j , eff . We also define an additional convergence parameter. Namely, we New J. Phys. 16 (2014) 073018 J Kaczmarczyk et al New J. Phys. 16 (2014) 073018 J Kaczmarczyk et al 16 New J. Phys. 16 (2014) 073018 J Kaczmarczyk et al 20The work was supported in part by the Foundation for Polish Science (FNP) under the 'TEAM' program, as well as by the project 'MAESTRO' from the National Science Centre (NCN), No DEC-2012/04/A/ST3/003420. Part of the computational work was performed on the Shiva supercomputer (IF UJ). One of the authors (JK) acknowledges the hospitality of the Leibniz Universit...

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Rotation of molecules embedded in He nanodroplets is explored by a combination of fs laserinduced alignment experiments and angulon quasiparticle theory. We demonstrate that at low fluence of the fs alignment pulse, the molecule and its solvation shell can be set into coherent collective rotation lasting long enough to form revivals. With increasing fluence, however, the revivals disappear -instead, rotational dynamics as rapid as for an isolated molecule is observed during the first few picoseconds. Classical calculations trace this phenomenon to transient decoupling of the molecule from its He shell. Our results open novel opportunities for studying non-equilibrium solute-solvent dynamics and quantum thermalization.

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Manganese, iron, and cobalt model spinel catalysts were systematically investigated for understanding the roots of their divergent performance in N2O decomposition. The catalysts were characterized by XRD, RS, N2-BET, SEM, and STEM/EELS techniques before and after the reaction. Their redox properties and the thermodynamic stability range were thoroughly examined by survey and narrow scan TPR/TPO cycles. The results were accounted for by the constructed size-dependent Ellingham diagrams. It was shown that Fe3O4 and Mn3O4 spinels exhibit redox-labile Mn2+/Mn3+ and Fe2+/Fe3+constituents, and under the conditions of the deN2O reaction these catalysts have a pronounced tendency for stoichiometric overoxidation. The redox properties of Co3O4 are highly anisotropic, with Co2+ being reluctant to undergo oxidation but Co3+ being prone to easy reduction. The stability of the Co3O4 catalyst is then controlled by partial reduction of octahedral Co3+ cations, due to the surface oxygen release at elevated temperatures in lean oxygen environments. The N2O decomposition was studied by temperature-programmed surface reaction (TPSR) and pulse experiments using 18O labeling of the catalysts. It was shown that Co3O4 provides a sustainable redox Co3+/Co4+ couple for catalytic decomposition of N2O, which operates along a reversible one-electron process, leading to formation of O– surf intermediates that recombine next into dioxygen. As the reaction temperature increases, the deN2O mechanism evolves from suprafacial to intrafacial recombination of the oxygen intermediates. Fe3O4 decomposes nitrous oxide in a stoichiometric way via irreversible two-electron reduction of oxygen intermediates into O2–, giving rise to lattice expansion and formation of a γ-Fe2O3 shell, as discerned by Raman spectroscopy. Postreaction STEM/EELS imaging confirmed a magnetite-core and a maghemite-shell morphology of the catalyst grains. A similar tendency for autogenous oxidation was observed for Mn3O4, yet a rather weak thermodynamic driving force makes this catalyst kinetically more stable. At higher reaction temperatures, the incipient γ-Mn2O3 layer may be decomposed back to the parent Mn spinel, when oxygen pressure is low. To quantify gradual oxidation of the investigated spinels during the N2O decomposition, size-dependent thermodynamic 3D diagrams were developed and used for rationalization of the experimental observations. The obtained results reveal the dynamic nature of the investigated spinels under varying redox conditions and explain the remarkable performance of Co3O4 in comparison to Fe3O4 and Mn3O4. The catalytic behavior of the latter two spinels is actually governed by a sesquioxide shell, produced spontaneously in the course of the deN2O reaction.