In this work, we present the results of a large-scale, semiempirical LocalSCF quantum mechanical study of GroEL-GroES chaperonin in solution containing 2,481,723 atoms. We find that large biological systems exhibit strong quantum mechanical character, the extent of which was not previously known. Our data show that protein transfers -743 electron units of charge to solvent, which is not described by classical force fields. Contrary to the commonly held belief, which is based on classical mechanics, our computational data suggest that the quantum mechanical effects of charge transfer increase with the size of biological systems. We show that the neglect of charge transfer in classical force fields leads to significant error in the electrostatic potential of the macromolecule. These findings illustrate that a quantum mechanical framework is necessary for a realistic description of electrostatic interactions in large biological systems.
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http://dx.doi.org/10.1021/jp211385e | DOI Listing |
J Chem Phys
January 2025
Theoretical and Computational Physics Section, Raja Ramanna Centre for Advanced Technology, Indore 452013, India.
The orbital-free density functional theory (OF-DFT) based method is a convenient tool to carry out electronic structure calculations scaling almost linearly with the number of electrons. However, the main impediment in the application of this method is the unavailability of the accurate form for the non-interacting kinetic energy functional in terms of electron density. The Pauli kinetic energy functional is the unknown part of the kinetic energy functional, and the corresponding Pauli potential appears in the governing Euler equation.
View Article and Find Full Text PDFAdv Mater
January 2025
State Key Laboratory for Manufacturing Systems Engineering, Electronic Materials Research Laboratory, Key Laboratory of the Ministry of Education, School of Electronic Science and Engineering, Xi'an Jiaotong University, Xi'an, 710049, China.
Large low-field magnetoresistance (LFMR, < 1 T), related to the spin-disorder scattering or spin-polarized tunneling at boundaries of polycrystalline manganates, holds considerable promise for the development of low-power and ultrafast magnetic devices. However, achieving significant LFMR typically necessitates extremely low temperatures due to diminishing spin polarization as temperature rises. To address this challenge, one strategy involves incorporating Ruddlesden-Popper structures (ABO):AO, which are layered derivatives of perovskite structure capable of potentially inducing heightened magnetic fluctuations at higher temperatures.
View Article and Find Full Text PDFPhys Chem Chem Phys
January 2025
King Abdullah University of Science and Technology (KAUST), Physical Science and Engineering Division (PSE), Thuwal 23955-6900, Saudi Arabia.
Employing density functional theory for ground state quantum mechanical calculations and the non-equilibrium Green's function method for transport calculations, we investigate the potential of CdS, ZnS, CdZnS, and ZnCdS as tunnel barriers in magnetic tunnel junctions for spintronics. Based on the finding that the valence band edges of these semiconductors are dominated by p orbitals and the conduction band edges by s orbitals, we show that symmetry filtering of the Bloch states in magnetic tunnel junctions with Fe electrodes results in high tunneling magnetoresistances and high spin-polarized current (up to two orders of magnitude higher than in the case of the Fe/MgO/Fe magnetic tunnel junction).
View Article and Find Full Text PDFNano Lett
January 2025
Center for Spintronics and Quantum Systems, State Key Laboratory for Mechanical Behavior of Materials, School of Materials Science and Engineering, Xi'an Jiaotong University, Xi'an, Shaanxi 710049, China.
The ferroelectric tunnel junction (FTJ) is a competitive candidate for post-Moore nonvolatile memories due to its low power consumption and nonvolatility, with its performance being strongly dependent on the conditions for contact between the ferroelectric material and the metal electrode. The development of two-dimensional materials in recent years has offered new opportunities such as functional metal layers, which is challenging for traditional FTJ systems. Here, we introduce the newly discovered ferroelectric metal WTe as the electrode to construct WTe/α-InSe/Au ferroelectric semiconductor junctions.
View Article and Find Full Text PDFiScience
January 2025
School of Mathematics and Statistics, Zhengzhou University, Zhengzhou 450001, China.
This study introduces a hybrid network model for phase classification, integrating quantum networks and complex-valued neural networks. This architecture uses elemental composition as its only input, eliminating complex feature engineering. Parameterized quantum networks handle sparse elemental data and convert data from real to complex domains, increasing information dimensionality.
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