Hydrodynamics and proper vibrations of quantum liquids with conformational degrees of freedom

The order parameters are constructed for a Fermi liquid with conformational degrees of freedom. Based on them, additional thermodynamic parameters were introduced: the spin unit vector dα (determining the anisotropy in the spin subspace), the unit spatial vectors mi and ni (determining the anisotropy in space), and also three scalar parameters determining the shape of the Cooper pair u, v, q ( first two items are half-axes of ellipsoid of Cooper pair and last item is mutual orientation in space of these half axes). The symmetry properties of the order parameter operator are considered. The equations of ideal hydrodynamics of a Fermi liquid are derived taking into account the influence of conformational degrees of freedom. By conformational degrees of freedom should be understood the parameters associated with the shape and size of the Cooper pair. Expressions are obtained for the flows of thermodynamic quantities of such a Fermi liquid in terms of the density of the energy functional. The energy functional depends both on the additive integrals of motion (classical fluid parameters) and on conformational parameters. The dispersion equation of such a liquid is obtained for a model representation of the energy functional (the work was performed as part of the Fermi-liquid approach). The dispersion equation includes spin modes, first, second, and third sounds. The dispersion equation for the spatial subsystem, including the first, second, and third sounds characteristic of superfluid systems, is analyzed. Particular solutions of the dispersion equation are simulated using the Maple software package (several 3D figures are given for the angular dependence of the speeds of 1 and 2 sounds in a spherical coordinate system). All of the above allows us to conclude that such a Fermi liquid can be considered as a superfluid liquid crystal of a nematic type. The presence of conformational parameters distinguishes the considered phase from the F phase of a superfluid Fermi liquid.

Conformational Entropy as a Means to Control the Behavior of Poly(diketonenamine) Vitrimers In and Out of Equilibrium

Here we show how to control the thermomechanical behavior of vitrimers, both in and out of equilibrium, by incorporating into the dynamic covalent network linear polymer segments varying in both molecular weight (MW = 0–12 kg mol–1) and conformational degrees of freedom. While increasing MW of linear segments predictably yields a lower storage modulus (E’) at the rubbery plateau after softening above the glass transition (Tg), due to the lower network density, we further find that both Tg and the characteristic time (t*) of stress-relaxation when deformed are independently governed by the conformational entropy of the embodied linear segments. We also find that activation energies (Ea) for vitrimer bond exchange in the solid-state are lower, by as much as 19 kJ mol−1, for networks incorporating flexible chains, and that the network’s topology freezing temperature (Tv) decreases with increasing MW of flexible linear segments, but increases with increasing MW of stiff linear segments. Therefore, the dynamics of vitrimer reconfigurability are influenced not only by the energetics of associative bond exchange for a given network density, but also foundationally by the entropy of polymer chains within the network.

Conformational Entropy as a Means to Control the Behavior of Poly(diketonenamine) Vitrimers In and Out of Equilibrium

Here we show how to control the thermomechanical behavior of vitrimers, both in and out of equilibrium, by incorporating into the dynamic covalent network linear polymer segments varying in both molecular weight (MW = 0–12 kg mol–1) and conformational degrees of freedom. While increasing MW of linear segments predictably yields a lower storage modulus (E’) at the rubbery plateau after softening above the glass transition (Tg), due to the lower network density, we further find that both Tg and the characteristic time (t*) of stress-relaxation when deformed are independently governed by the conformational entropy of the embodied linear segments. We also find that activation energies (Ea) for vitrimer bond exchange in the solid-state are lower, by as much as 19 kJ mol−1, for networks incorporating flexible chains, and that the network’s topology freezing temperature (Tv) decreases with increasing MW of flexible linear segments, but increases with increasing MW of stiff linear segments. Therefore, the dynamics of vitrimer reconfigurability are influenced not only by the energetics of associative bond exchange for a given network density, but also foundationally by the entropy of polymer chains within the network.

Computational high-throughput screening of polymeric photocatalysts: exploring the effect of composition, sequence isomerism and conformational degrees of freedom

We discuss a low-cost computational workflow for the high throughput screening of polymeric photocatalysts.

Pd doping, conformational, and charge effects on the dichroic response of a monolayer protected Au38(SR)24 nanocluster

TDDFT simulations of the absorption and CD spectra of a Pd2Au36(SC2H4Ph)24 monolayer-protected cluster (MPC) are carried out with the aim of investigating the effects of doping, conformational degrees of freedom of the thiolates’ end-groups, and charge states on its chiro-optical response.

Computational High-Throughput Screening of Polymeric Photocatalysts: Exploring the Effect of Composition, Sequence Isomerism and Conformational Degrees of Freedom

We discuss a low-cost computational workflow for the high-throughput screening of polymeric photocatalysts and demonstrate its utility by applying it to a number of challenging problems that would be difficult to tackle otherwise. Specifically we show how having access to a low-cost method allows one to screen a vast chemical space, as well as to probe the effects of conformational degrees of freedom and sequence isomerism. Finally, we discuss both the opportunities of computational screening in the search for polymer photocatalysts, as well as the biggest challenges.

Computational High-Throughput Screening of Polymeric Photocatalysts: Exploring the Effect of Composition, Sequence Isomerism and Conformational Degrees of Freedom

We discuss a low-cost computational workflow for the high-throughput screening of polymeric photocatalysts and demonstrate its utility by applying it to a number of challenging problems that would be difficult to tackle otherwise. Specifically we show how having access to a low-cost method allows one to screen a vast chemical space, as well as to probe the effects of conformational degrees of freedom and sequence isomerism. Finally, we discuss both the opportunities of computational screening in the search for polymer photocatalysts, as well as the biggest challenges.

Computational High-Throughput Screening of Polymeric Photocatalysts: Exploring the Effect of Composition, Sequence Isomerism and Conformational Degrees of Freedom

We discuss a low-cost computational workflow for the high-throughput screening of polymeric photocatalysts and demonstrate its utility by applying it to a number of challenging problems that would be difficult to tackle otherwise. Specifically we show how having access to a low-cost method allows one to screen a vast chemical space, as well as to probe the effects of conformational degrees of freedom and sequence isomerism. Finally, we discuss both the opportunities of computational screening in the search for polymer photocatalysts, as well as the biggest challenges.

Computational High-Throughput Screening of Polymeric Photocatalysts: Exploring the Effect of Composition, Sequence Isomerism and Conformational Degrees of Freedom

We discuss a low-cost computational workflow for the high-throughput screening of polymeric photocatalysts and demonstrate its utility by applying it to a number of challenging problems that would be difficult to tackle otherwise. Specifically we show how having access to a low-cost method allows one to screen a vast chemical space, as well as to probe the effects of conformational degrees of freedom and sequence isomerism. Finally, we discuss both the opportunities of computational screening in the search for polymer photocatalysts, as well as the biggest challenges.

Computational High-Throughput Screening of Polymeric Photocatalysts: Exploring the Effect of Composition, Sequence Isomerism and Conformational Degrees of Freedom

We discuss a low-cost computational workflow for the high-throughput screening of polymeric photocatalysts and demonstrate its utility by applying it to a number of challenging problems that would be difficult to tackle otherwise. Specifically we show how having access to a low-cost method allows one to screen a vast chemical space, as well as to probe the effects of conformational degrees of freedom and sequence isomerism. Finally, we discuss both the opportunities of computational screening in the search for polymer photocatalysts, as well as the biggest challenges.