Modeling of the water layer on the surface of airgel nanopores has been carried out. The interaction potentials between incident water molecule and water molecule adsorbed on the nanopore surface were calculated by the use B3LYP/6-31 + G (d) method. An analytical form of the isotropic potential was obtained.
The method to calculate the dipole moment of X<sub>2</sub>-Y and X<sub>2</sub>-Y<sub>2</sub> dimers as a function of their geometrical parameters is
proposed. This method allows taking the internuclear distance in X<sub>2</sub> (Y<sub>2</sub>) molecule into account. Analytical expressions
for the dipole moment surface of the complexes are suggested. The method is applied for the calculation of the dipole
moment surface of N<sub>2</sub>-Y (Y = He, Ne, Ar, Kr) and N<sub>2</sub>-N<sub>2</sub> dimers.
Method of scattering waves with the Gunnarson-Lundkvist of exchange-correlation potential was realized in software.
The dipole moment function of LiH molecule in the range from small to equilibrium internuclear separations (0.3÷3.0
a.u.) were calculated. The bond length of Li<sub>2</sub>, the bond length and bond energy of Ti<sub>2</sub> and Cr<sub>2</sub> were calculated. The
electron density distribution and magnetic properties of the nanotube fragment of Fe<sub>32</sub>Si<sub>5</sub> have been considered.
The energy levels and wave functions of ground electronic configurations of 104 atoms of the Periodic table were
calculated using the Hartree-Fock method with the local approximations of exchange potential. Influence of six
exchange-correlation potentials on the formation of electronic states was investigated to optimize a zero approach choice.
The results allowed constructing a base of atomic spectral data of the energy levels, wave functions, electron densities
and quadrupole moments of atoms. Calculation results for the atoms of second period (Li - Ne) and the first transition
row (Sc - Zn) of Periodic table are given.
The report is devoted to the research of IR spectrum of high temperature (T < 3000 K) and thermodynamic inhomogeneous heat water vapor. The physical models of the description factors of absorption and emissivity within the framework of direct accounts line by line are discussed. The main attention is given to the form of the spectral lines parameters databases of water vapor based on generating information system HOTGAS-H<sub>2</sub>0. Assuming that the radiation diffusion and local thermodynamic balance are fulfilled inside a layer, the emissivity calculations for various path conditions of concentration and temperatures 300-3000 K are designed. Thus, stratified environment formed by an user was simulated by layers of various thickness. Approximations of absorption coefficients simplifying considerably calculations are proposed. The estimation of the nonselective absorption of water vapor in the range 8-12 microns for temperatures I 500-3000 K are given for the first time.
The semiempirical method of construction of the electronic polarizability functions for heteronuclear diatomic molecule
in the piecewise-continuous form is discussed. The polarizability functions obtained have true asymptotic behaviour as
for small as for large internuclear separations <i>R</i> and describe correctly the polarizability of a molecule in a vicinity of
the equilibrium internuclear distance. To describe the polarizability functions for large separations, the DID interactions
of atoms have been taken into account, and the exchange interactions of atoms have been considered by asymptotic
methods. The method has been applied to calculate the polarizability functions of HF and HCI molecules in a range
<i>R</i> ∈ [0,∞).
The dipole moment function μ(R) of the X<sup>1</sup>Σ<sup>+</sup> electronic state of LiH molecule for small internuclear separation <i>R </i>has been determined. The calculations were carried out within the framework of the model of a united atom. The wave
functions and energy levels of the united Be atom were calculated by <i>ab initio </i>HF method. The dipole moment function
obtained at R -> 0 has the form μ(R) = AR<sup>3</sup>. The numeric value of the coefficient <i>A</i> has been obtained. The limits of an
applicability of the united atom approximation for the calculation of the dipole moment of LiH molecule were
determined.
In the framework of the DID model the analytical expressions for the tensor components of the dynamic polarizability
of X<sub>2</sub>...Y dimers have been obtained taking into account the size of X<sub>2</sub> molecule. The polarizability functions of the complexes depend on their configuration and dynamic polarizabilities of the atom Y and the molecule X<sub>2</sub>. The dynamic polarizabilities of the complexes X<sub>2</sub>...Y (X<sub>2</sub> = N<sub>2</sub>, 0<sub>2</sub> and Y = He, Ne, Ar, Kr, Xe) have been calculated.
Software developed by authors for <i>ab initio </i>calculations of energy parameters and physical properties of the microsystems using the scattered wave method allows investigating the changes of their atom-molecular physical characteristics depending on the sizes and dimensions of the systems: atom-molecule-cluster-nanostructure-crystal. Any atoms of Periodic Table calculated in the nonrelativistic approach can form the structure of the considered systems. The work aims to study theoretically the energy and electric characteristics of the atom-molecular systems when the
conditions of three-dimensional regulating are fulfilled and the environment are varied. The original software is used to unify the calculation procedure for any state of a system. The regularities of forming of the electronic structure for the microsystems Li - Li<sub>2</sub> - Li<sub>9</sub> - Li<sub>15</sub> - Li<sub>91</sub> have been studied. The influence of an environment on the three-dimensional regulating of atoms was analyzed. Also, the differences in the electronic structure of the subsystems within the volume and on the surface were studied. The electronic energies of the structural modifications for the three-dimensional systems were compared. The peculiarities of structure of the heteronuclear systems, using the molecule LiH as an example, have been considered. The problem of a choice of the exchange-correlation contribution into the MT-potential was analyzed. The role of interactions of the valence and core states of a molecule to form the dipole moment
function depending on the internuclear separations is discussed.
The dependence of the polarizability of the molecular complexes X<sub>2</sub>---Y from the distance between the Y atom and X<sub>2</sub> molecule, from the internuclear separation of the molecule X<sub>2</sub>, and the orientation of the molecule X<sub>2</sub> in the complex has been theoretically investigated. The polarizability calculations of the complex were carried out within the framework of modified DID model in which the molecule forming the dimer is represented as two anisotropic effective atoms. The polarizability of these effective atoms was determined by the polarizability of the X<sub>2</sub> molecule and its orientation in the dimer. The polarizabilities of the complexes X<sub>2</sub>---Y (X<sub>2</sub>.=N<sub>2</sub>, O<sub>2</sub> and Y = He, Ne, Ar, Kr, Xe) have been calculated.
In the framework of the semiempirical method the dipole moment function of the <i>LiH</i> molecule being in the ground electronic state has been obtained. This function is represented in the piecewise continuous curve in a range of internuclear distances <i>R</i> = [0,∞). The function has correct asymptotic behavior as for small as for large <i>R</i> and coincides with the experimental one in a vicinity of the equilibrium internuclear distance <i>R<sub>e</sub></i>. The experimental value of the second derivative of dipole moment function in the point <i>R<sub>e</sub></i> has been obtained, and the coefficient <i>C<sub>7</sub></i> determining behavior of the dipole moment function for large <i>R</i> as <i>C<sub>7</sub></i> / <i>R<sup>7</sup></i> was found.
The semiempirical calculation method of the dynamic polarizability function for the diatomic molecule has been proposed. In a frame of this method the transformation low of the static polarizability function for a molecule with the frequency of the incident field was shown. The static polarizability of a molecule has been represented as a piecewise continuous function which has correct asymptotic behaviour for small and large internuclear distances, and describes correctly the polarizability in a vicinity of the equilibrium internuclear distance for a molecule. The method was tested on the hydrogen molecule for which a good agreement of the calculated dynamic polarizability with the correct <i>ab initio</i> calculations has been obtained. The calculation results of the dynamic polarizability functions for the N<sub>2</sub> molecule for any internuclear distances in a frequency range 0-60000 cm<sup>-1</sup> are given.
Proc. SPIE. 5396, Tenth Joint International Symposium on Atmospheric and Ocean Optics/Atmospheric Physics. Part I: Radiation Propagation in the Atmosphere and Ocean
The semiempirical method for calculation of the dipole moment functions for NO and CO molecules as a piecewise-continuous ones has been developed. The dipole moment functions found exhibit physically correct asymptotic behaviour at small and large internuclear separations and agree with the dipole moment functions near the nuclear equilibrium position of the molecule. In the framework of the approach the multipole and exhange interactions have been considered to improve the dipole moment function under large internuclear distances including the range of small overlapping of the electronic shells for the interacting atoms.
Proc. SPIE. 5396, Tenth Joint International Symposium on Atmospheric and Ocean Optics/Atmospheric Physics. Part I: Radiation Propagation in the Atmosphere and Ocean
Theoretically the influence of the nuclear vibrations of the N<sub>2</sub> and O<sub>2</sub> molecules on the polarizability of the molecular complexes (N<sub>2</sub>)<sub>2</sub> and (O<sub>2</sub>)<sub>2</sub> has been investigated. The polarizability calculations of the dimers were carried out within the framework of the DID model in which the molecules, forming the dimer, are represented as anisotropic effective atoms, and their polarizability coincides with the polarizability of the molecules. Within the framework of the model coinsidered the (N<sub>2</sub>)<sub>2</sub> and (O<sub>2</sub>)<sub>2</sub> dimer polarizability functions have been obtained. For some their configurations the first derivatives of polarizability with respect to the internuclear distances have been calculated.
Proc. SPIE. 5396, Tenth Joint International Symposium on Atmospheric and Ocean Optics/Atmospheric Physics. Part I: Radiation Propagation in the Atmosphere and Ocean
The semiempirical method for calculation of the polarizability functions for diatomic homonuclear molecules as piecewise-continuous ones has been developed. The polarizability functions found exhibit physically correct asymptotic behaviour at small and large internuclear separations and agree with the polarizability functions near the nuclear equilibrium position of the molecule. In the framework of the approach the exchange interactions have been considered to improve the polarizability functions under large internuclear distances including the range of small overlapping of the electronic shells of the interacting atoms. The method has been applied to calculate the polarizability functions of the N<sub>2</sub> and O<sub>2</sub> molecules in the internuclear distances Rε[0,∞).
Proc. SPIE. 5026, Ninth Joint International Symposium on Atmospheric and Ocean Optics/Atmospheric Physics. Part I: Radiation Propagation in the Atmosphere and Ocean
The new semiempirical calculation method of the polarizability function for diatomic homonuclear molecules in a range R∈(0,∞ ) has been developed. The method is based on the use of the known polarizability function for small R, the polarizability values and their polarizability derivatives in the equilibrium internucelar distance and the elaborated polarizability function of the interacting oriented atoms under greater R, which comprises the atomic polarizability change under their approach, as well as takes into account their multipole interactions. Account of the multipole interaction of atoms is carried out within the framework of the model of two interacting dielectric spheres. The method is tested by the molecule H<sub>2</sub> and applied to the calculation of polarizability functions for the N<sub>2</sub> and O<sub>2</sub> molecules.
Proc. SPIE. 5026, Ninth Joint International Symposium on Atmospheric and Ocean Optics/Atmospheric Physics. Part I: Radiation Propagation in the Atmosphere and Ocean
In a frame of DID model the calculation method of the temperature dependence of the dimer polarizability has been proposed. The temperature dependence is caused by the statistical average of the electronic polarizability over the vibrational rotational states of different dimer configurations. In this way every molecule of the dimer is considered like any effective atom having the same polarizability tensor as the molecule. The interactions between the effective atoms in a dimer are taken in the form of Lennard-Jones function. The method proposed was applied to calculate of the temperature dependence for (N<sub>2</sub>)<sub>2</sub> and (O<sub>2</sub>)<sub>2</sub> polarizability invariants.
Proc. SPIE. 5026, Ninth Joint International Symposium on Atmospheric and Ocean Optics/Atmospheric Physics. Part I: Radiation Propagation in the Atmosphere and Ocean
The new semiempirical calculation method of the dipole moment function for diatomic molecules in a range R∈(0,∞ ) has been developed. The method unlike Pade approximants allows to represent the dipole moment function by the piecewise-continuous function which has the correct asymptotic behavior for small and large internuclear separations and agrees with the empirical dipole moment function about nuclei equilibrium separation. The method is applied to the hydrogen halides.
The influence of vibration-rotation interactions and anharmonicities on the polarizabilities matrix elements and scattering cross-sections of N<SUB>2</SUB> and O<SUB>2</SUB> molecules for vibrational transitions v implies v, v+1, v+2, v+3 were investigated.
The dependence of N<SUB>2</SUB> - N<SUB>2</SUB>, O<SUB>2</SUB> - O<SUB>2</SUB>, and N<SUB>2</SUB> - O<SUB>2</SUB> pairs polarizability in versus their intermolecular distance in a frame of classical Silberstein approximation was investigated. The polarizability tensor components of O<SUB>2</SUB> and N<SUB>2</SUB> dimers at the stable equilibrium configurations were calculated.
The new calculation approach of water vapor rotational energy levels using symmetric top model for K<SUB>a</SUB>>=J/2>>1 has proposed. The rotational spectroscopic parameters of the Pade-approximation for ground vibrational state of H<SUB>2</SUB>O molecule in the frame of this model was obtained. The absorption coefficient of water vapor in a spectral range 850-920 cm<SUP>-1</SUP> was calculated for 1000 - 10000 K temperatures.
The temperature dependence of polarizabilities of gaseous N<SUB>2</SUB> and O<SUB>2</SUB> in a wide temperature range was calculated. These calculations are based on the experimental values of polarizability derivatives. The temperature dependence obtained has been given in a simple form.