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Metastable states of warm dense hydrogen
Interfacial Phenomena and Heat Transfer. 2017. Vol. 5. No. 3. P. 165-171.
Warm dense hydrogen is investigated by ab initio molecular dynamics simulations in the region of fluid–fluid phase
transition. The method of getting adjacent metastable states is developed. The metastable states are successfully obtained in the region of densities from 0.920 to 0.970 g/cm3 and pressures from 1850 kbar to 2150 kbar along an example of 1000K isotherm. The states have similar pair correlation function as equilibrium ones before the transition. The existence of metastable states provides possible physical reasons of the remarkable differences between phase transition parameters obtained by three experimental groups.
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
Norman G., Saitov I., Journal of Physics: Conference Series 2018 Vol. 946 No. 012121
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 H2+ and H3+ . Conventional ab initio quantum modeling is applied. Proton pair correlation functions (PCF) obtained are used for the nonconventional diagnostics of the phase ...
Added: November 29, 2017
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
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
Zhang L., Vasenko A.S., Zhao J. et al., The Journal of Physical Chemistry Letters 2019 Vol. 10 No. 5 P. 1083-1091
An attractive two-dimensional semiconductor with tunable direct bandgap and high carrier mobility, black phosphorus (BP) is used in batteries, solar cells, photocatalysis, plasmonics and optoelectronics. BP is sensitive to ambient conditions, with oxygen playing a critical role in structure degradation. Our simulations show that BP oxidation slows down charge recombination. This is unexpected, since typically ...
Added: February 19, 2019
He J., Vasenko A.S., Long R. et al., The Journal of Physical Chemistry Letters 2018 Vol. 9 No. 8 P. 1872-1879
We demonstrate that halide content strongly affects nonradiative electron–hole recombination in all-inorganic perovskite quantum dots (QDs). Using time domain density functional theory and nonadiabatic molecular dynamics, we show that replacing half of the bromines with iodines in a CsPbBr3 QD extends the charge carrier lifetime by a factor of 5, while complete replacement extends the ...
Added: March 31, 2018
Kolokolov I., Lebedev V., Gamba A. et al., Journal of Statistical Mechanics: Theory and Experiment 2009 P. P02019
Cell polarization plays a central role in the development of complex
organisms. It has been recently shown that cell polarization may follow from
the proximity to a phase separation instability in a bistable network of chemical
reactions. An example which has been thoroughly studied is the formation of
signaling domains during eukaryotic chemotaxis. In this case, the process of
domain ...
Added: February 7, 2017
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
Zubizarreta X., Chulkov E. V., Chernov I. P. et al., Physical Review B: Condensed Matter and Materials Physics 2017 Vol. 95 No. 235405 P. 235405-1-235405-15
A theoretical study of collective electronic excitations in free-standing Pb(111) thin films consisting of 1–5 monolayers (MLs) and a 21-ML film is presented. The calculations are carried out applying the linear response theory, with full inclusion of the electron band structure by means of a first-principles pseudopotential approach in a supercell scheme. In the case ...
Added: June 6, 2017
Li W., Vasenko A.S., Tang J. et al., The Journal of Physical Chemistry Letters 2019 Vol. 10 No. 20 P. 6219-6226
Lead halide perovskites constitute a very promising class of materials for a broad range of solar and opto-electronic applications. Perovskites exhibit many unusual properties, and recent experiments demonstrate an unusual temperature dependence of charge carrier lifetimes. Focusing on the all-inorganic CsPbBr3, and using a combination of ab initio nonadiabatic molecular dynamics and time-domain density functional ...
Added: September 30, 2019
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
Korsun O. M., Kalugin O. N., Vasenko A. S. et al., Journal of Physical Chemistry C 2016 Vol. 120 No. 46 P. 26514-26521
The influence of bare and solvated cations imbedded inside single-walled carbon nanotubes (SWCNTs) on the SWCNT electronic properties is studied by ab initio electronic structure calculations. The roles of ion charge and ion solvation are investigated by comparing Li+ vs Mg2+ and Li+ vs its solvatocomplex with two ethylene carbonate (EC) molecules, [Li(EC)2]+. Two achiral ...
Added: November 22, 2016
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
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
Fleita D., Norman Genri E., Pisarev Vasily V., Journal of Physics: Conference Series 2018 Vol. 946 No. 1 P. 012102-1-012102-7
This paper discusses the results of the application method of spatial correlation functions on a glass-forming liquid of a pure metal melt by performing molecular dynamics simulations. We define a high-order correlation function that quantifies a spatial correlation of single-particle displacements in liquids and amorphous systems. Time dependencies of the different 4-point spatial functions for ...
Added: October 31, 2018
Nuraliev M., Parashchuk O., Tukachev N. et al., Journal of Chemical Physics 2020 Vol. 153 Article 174303
Electron–phonon interaction strongly affects and often limits charge transport in organic semiconductors (OSs). However, approaches to its experimental probing are still in their infancy. In this study, we probe the local electron–phonon interaction (quantified by the charge-transfer reorganization energy) in small-molecule OSs by means of Raman spectroscopy. Applying density functional theory calculations to four series ...
Added: October 18, 2021
Norman G., Saitov I., Sartan R., Doklady Physics 2018 Vol. 63 No. 8 P. 313-316
Warm dense hydrogen is investigated by the ab initio molecular dynamics method near the fluid–
fluid phase transition. The metastable states are calculated along isotherms of 700 and 1000 K. The obtained
pressure ranges of metastable states are 0.47 and 0.32 Mbar, respectively. Their existence indicates that this
transition is a first-order phase transition. ...
Added: November 2, 2018
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., Доклады Российской академии наук. Физика, технические науки (ранее - Доклады Академии Наук. Физика) 2017 Т. 474 № 6 С. 687-691
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 ...
Added: December 2, 2017
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
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
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
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
Katushkina O. A., Quemerais E., Izmodenov V.V. et al., JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS 2017 Vol. 122 No. 11 P. 10921-10937
In this work, we present for the first time the Lyman α intensities measured by Voyager 1/UVS in 2003–2014 (at 90–130 AU from the Sun). During this period Voyager 1 measured the Lyman α emission in the outer heliosphere at an almost fixed direction close to the upwind (i.e.“ toward the interstellar flow). The data show an unexpected behavior in 2003–2009: the ...
Added: January 26, 2018