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## Критическая точка и механизм фазового перехода флюид-флюид в разогретом плотном водороде.

Doklady Physics. 2017. Т. 474. № 6. С. 687-691.

Norman G., Saitov I.

The density functional theory is used to calculate the equation of state and the proton-proton pair correlation functions in the range of hydrogen temperatures and densities where the fluid-fluid-phase transition is expected. The metastable states are considered. The critical temperature has been estimated to be ~4000 K. We propose a two-step mechanism: the partial ionization of molecules to produce ions H2+ at the phase transition followed by the formation of ions H3+.

Norman G., Saitov I., Доклады Российской академии наук. Физика, технические науки (ранее - Доклады Академии Наук. Физика) 2017 Т. 474 № 5 С. 553-557

The problem of the fluid–fluid phase transition in warm dense hydrogen/deuterium has been studied experimentally and theoretically in the best laboratories in the last decade. However, the nature of the phase transition remains unclarified. In this paper we put forward the new idea that H2 molecules are ionized at the phase transition to produce molecular ...

Added: December 2, 2017

Stegailov V., Zhilyaev P. A., Contributions to Plasma Physics 2015 Vol. 55 No. 2-3 P. 164-171

Non-equilibrium two-temperature warm dense metals consist of the ion subsystem that is subjected to structural transitions and involved in the mass transfer, and the electron subsystem that in various pulsed experiments absorbs energy and then evolves together with ions to equilibrium. Definition of pressure in such non-equilibrium systems causes certain controversy. In this work we ...

Added: March 15, 2017

Norman G., Saitov I., Stegailov V. et al., Physical Review E - Statistical, Nonlinear, and Soft Matter Physics 2015 Vol. 91 No. 023105 P. 1-10

Reflectivity of shocked compressed xenon plasma is calculated within the framework of the density functional theory approach. Dependencies on the frequency of incident radiation and on the plasma density are analyzed. The Fresnel formula for the reflectivity is used. The longitudinal expression in the long-wavelength limit is applied for the calculation of the imaginary part ...

Added: March 15, 2017

Norman G., Saitov I., Stegailov V., Contributions to Plasma Physics 2015 Vol. 55 No. 2-3 P. 215-221

Ab initio quantum modeling is applied to check the ideas that motivated studies of both plasma phase transition (PPT) and Brazhkin semiconductor-to-metal phase transition, and to analyze both similarity and difference between them as well as with the Wigner metallization. Electron density of states and the characteristic gap in it are investigated to verify the ...

Added: March 15, 2017

Stegailov V., Zhilyaev P., Molecular Physics 2016 Vol. 114 No. 3-4 P. 509-518

Warm dense matter is a peculiar state with solid densities and temperatures 1 − 100 eV. Its ab initio description waits united efforts of quantum chemistry, condensed matter and plasma physics. We use the finite temperature Kohn–Sham density functional theory (a ‘workhorse’ in this field) to study the pressure build-up with increase of electronic temperature in ...

Added: July 5, 2016

Saitov I., Журнал экспериментальной и теоретической физики 2020 Т. 157 № 3 С. 504-512

Density-functional theory (DFT) is applied to the calculation of the equation of state, the pair correlation
function (PCF), and the static electrical conductivity of solid hydrogen near the transition point to
the conducting state. It is found that the pressure versus density exhibits hysteresis at temperature of 100 K
under compression followed by expansion. The overlapping of the ...

Added: October 29, 2022

Norman G., Saitov I., Doklady Physics 2019 Vol. 64 No. 4 P. 145-149

—The structural transformation of solid hydrogen under compression along the isotherm of 100 K in
the region of transition into the conductive state was studied within the density functional theory. The pressure, the pair correlation function of protons, the density of electron states, and the electrical conductivity were calculated within a range of hydrogen densities from ...

Added: October 30, 2019

Medvedev M., Marjewski A., Gerasimov I. et al., Mendeleev Communications 2018 Vol. 28 No. 3 P. 225-235

The task of choosing a reliable density functional (DFT) approximation remains one of the most puzzling ones in quantum chemical modeling and materials simulations. Since DFT functionals are in general not systematically improvable, benchmarking them on specifically designed test sets is the usual way for identifying a method best suited for a particular purpose. To ...

Added: October 12, 2019

Medvedev M., Bushmarinov I., Sun J. et al., Science 2017 Vol. 355 No. 6320 P. 49-52

The theorems at the core of density functional theory (DFT) state that the energy of a many-electron system in its ground state is fully defined by its electron density distribution. This connection is made via the exact functional for the energy, which minimizes at the exact density. For years, DFT development focused on energies, implicitly ...

Added: October 12, 2019

Быстрый Р.Г., Лавриненко Я. С., Ланкин А. В. et al., Теплофизика высоких температур 2014 Т. 52 № 4 С. 494-503

Pressure fluctuations in equilibrium nonideal plasma are investigated by the method of classical molecular dynamics. Examples of plasma parameters at which the pressure fluctuation distribution function is not normal but can be approximated by the sum of two normal distributions were found. The electron-ion interaction is described by the Coulomb potential cutoff at the depth ...

Added: December 25, 2014

Heindl C., Peresypkina E., Virovets A. et al., Angewandte Chemie - International Edition 2017 Vol. 56 No. 43 P. 13237-13243

Pentaphosphaferrocenes [CpRFe(η5-P5)] (1) and CuI halides are excellent building blocks for the formation of discrete supramolecules. Herein, we demonstrate the potential of Cu(CF3SO3) for the construction of the novel 2D polymer [{Cp*Fe(μ4,η5:1:1:1-P5)}{Cu(CF3SO3)}]n (2) and the unprecedented nanosphere (CH2Cl2)1.4@[{CpBnFe(η5-P5)}12{Cu(CF3SO3)}19.6] (3). The supramolecule 3 has a unique scaffold beyond the fullerene topology, with 20 copper atoms statistically ...

Added: October 12, 2019

Norman G., Saitov I., Journal of Physics: Conference Series 2016 Vol. 774 No. 012015 P. 1-8

An analysis is presented of experimental data where fluid–fluid phase transitions are observed for different substances at high temperatures with triple points on melting curves. Viscosity drops point to the structural character of the transition, whereas conductivity jumps remind of both semiconductor-to-metal and plasma nature. The slope of the phase equilibrium dependencies of pressure on ...

Added: March 30, 2017

Norman G., Saitov I., Stegailov V. et al., Contributions to Plasma Physics 2013 Vol. 53 No. 4-5 P. 300-310

Warm dense matter conductivity and reflectivity are investigated by means of density functional theory. Both one- and two-temperature cases are considered. One-temperature mode is related to equilibrium state where temperature of electrons and ions are equal. As an example of one-temperature system xenon plasma is studied. The reflectivity of shock-compressed dense xenon plasma is calculated ...

Added: March 19, 2014

Norman G., Saitov I., Sartan R., Contributions to Plasma Physics 2019 Vol. 59 No. 6 P. e201800173

Warm dense hydrogen is studied in the region of fluid–fluid phase transition within
the framework of the density functional theory. We report a procedure of obtaining
metastable states and calculate the equation of state. Metastable states are diagnosed by pair correlation functions and values of conductivity. We obtain a strong
overlapping through the density of metastable and equilibrium ...

Added: October 30, 2019

Ofengeim D., Physical Review D - Particles, Fields, Gravitation and Cosmology 2020 Vol. 101 No. 10 P. 103029

I have demonstrated the existence of a tight correlation between the mass, radius, central density, and pressure of maximum-mass neutron stars modeled using diverse baryonic equations of state. A possible explanation for these correlations is provided. Simple analytic forms of such correlations are suggested and compared with observational constraints on the maximum mass of neutron ...

Added: November 11, 2020

Norman G., Saitov I., Contributions to Plasma Physics 2018 Vol. 58 No. 2-3 P. 122-127

A new idea is developed that the fluid–fluid phase transition in warm dense hydrogen
is related to the partial ionization of molecular hydrogen H2 with formation of
molecular ions H+2 and H+3 . Conventional ab initio quantum modelling is applied.
The proton–proton pair correlation functions (PCFs) obtained are used for the
non-conventional diagnostics of the phase transition and elucidation ...

Added: June 8, 2018

Cruchter T., Medvedev M., Shen X. et al., ACS Catalysis 2017 Vol. 7 No. 8 P. 5151-5162

Herein, we report about the design, synthesis, and application of a nucleophilic octahedral chiral-only-at-metal iridium(III) complex. We demonstrate that the enantiopure form of this complex serves as an efficient catalyst for the asymmetric Steglich rearrangement of O-acylated azlactones (up to 96% ee and 99% yield) and the related asymmetric Black rearrangement of O-acylated benzofuranones (up to 94% ...

Added: October 12, 2019

Malova H. V., V. Yu. Popov, Grigorenko E. E. et al., Astrophysical Journal 2017 Vol. 834 No. 34 P. 1-9

We investigate quasi-adiabatic dynamics of charged particles in strong current sheets (SCSs) in the solar wind, including the heliospheric current sheet (HCS), both theoretically and observationally. A self-consistent hybrid model of an SCS is developed in which ion dynamics is described at the quasi-adiabatic approximation, while the electrons are assumed to be magnetized, and their ...

Added: February 15, 2017

Akchurin I., Yakhutina A., Bochkov A. et al., Journal of Molecular Structure 2018 Vol. 1160 P. 215-221

Novel push-pull fluorescent dyes – 7-(diethylamino)furo- and 7-(diethylamino)thieno[3,2-c]coumarins derivatives have been synthesized using formyl derivatives of furo- and thieno[3,2-c]coumarins as starting materials. Electron absorption and fluorescent spectra of the dyes have been recorded in different solvents. Effects of dyes structure and solvent on their spectral characteristics were analyzed. The fusion of five-membered heterocycle to coumarin ...

Added: October 12, 2019

T.V. Pavlova, G.M. Zhidomirov, K.N. Eltsov, The Journal of Physical Chemistry C (США) 2018 Vol. 122 No. 3 P. 1741-1745

This paper presents a density functional theory study for phosphine adsorption on a Si(001)-2 × 1 surface covered by a chlorine monolayer, including adsorption on local defects, i.e., mono- and bivacancies in the adsorbate layer (Cl, Cl2), and combined vacancies with removed silicon atoms (SiCl, SiCl2). Activation barriers were found for the adsorbing PH3 to dissociate ...

Added: January 10, 2019

Norman G., Saitov I., Contributions to Plasma Physics 2019 Vol. 59 No. 6 P. e201800182

At first, we present a brief review of the problem. Then, we consider plasma phase transition (PPT) as a mechanism of the first order fluid–fluid phase transition in warm dense hydrogen. The pros and cons are analysed. The properties of warm dense hydrogen are investigated by ab initio methods of molecular dynamics using the density ...

Added: October 30, 2019

Saitov I., Molecular Physics 2016 Vol. 114 No. 3-4 P. 446-452

Density functional theory (DFT) is applied for the calculation of the dielectric function (DF), reflectivity,
conductivity, plasma frequency and effective free electron density of warm dense matter
(WDM). Shock-compressed xenon plasma and warm dense hydrogen are considered. The longitudinal
expression in the long wavelength limit is applied for the calculation of the imaginary part of
the DF. The real ...

Added: March 30, 2017

Norman G., Saitov I., Sartan R., Journal of Physics: Conference Series 2019 Vol. 1147 No. 012003 P. 1-6

The warm dense hydrogen is studied by means of the ab initio molecular dynamics
simulation in the region of fluid–fluid phase transition. The metastable states of two isotherm
of 700 and 1000 K are calculated. The metastable ranges by pressure are 470 and 320 kbar
respectively. The existence of metastability is a strong criterion that the transition is ...

Added: October 30, 2019

Norman G., Saitov I., Успехи физических наук 2021 Т. 191 № 11 С. 1153-1186

Recently developed experimental methods for the generation and diagnostics of nonideal plasma and warm dense
matter are reviewed. Modern theoretical methods applied to solve the problem of fluid±fluid phase transitions, including the plasma phase transition, are considered. Quantum simulation methods and the results obtained in the chemical model of plasma are analyzed. Particular attention is paid ...

Added: October 29, 2022