Bond-charge calculation of electro-optic coefficients of diatomic crystals

A theoretical method has been set up to calculate the electrooptic tensor coefficients r(ijk), based on the Phillips-Van Vechten (PV) dielectric theory and the Levine bond charge model, Starting from the crystal structure data and only introducing the experimentally determined optical permittivity and dielectric constant, the electro-optic tensor coefficients r(ijk) can be quantitatively predicted, The theoretical calculations are in good agreement with experiment in the case of zinc blende and wurtzite crystals, For zinc blende crystals, the effects of covalent radii on the linear electro-optic coefficients are discussed. (C) 1997 Academic Press.

Calculation of the nonlinear optical coefficient of the NdAl3(BO3)(4) crystal

For the first time, we present the calculation of the nonlinear optical coefficient of the NdAl3(BO3)(4) (NAB) crystal from a systematic and quantitative standpoint. Based on the dielectric theory of complex crystals and the Levine bond charge model, the method of calculation of the second-order nonlinear optical tensor coefficients of complex crystals has been given systematically. The chemical bond parameters and linear and nonlinear susceptibilities of the NAB crystal have been calculated in detail, and the calculated value of d(11)(NAB) is -5.81 x 10(-9) esu, which agrees with the measured value of 4.06 x 10(-9) esu.

CALCULATION METHOD OF LATTICE ENERGY ON COMPLEX-CRYSTALS

In this paper, based on the consideration of covalent behavior of adjacent ions in crystals, a calculation formula of lattice energy was proposed. In which, the concept of ionic effective valence and the empirical formula covalent energy were introduced,

A STUDY ON CH5O+ IONS IN GAS PHASE CID EYPERIMENT AND QUANTUM CHEMISTRY CALCULATION

The structures of CH5O+ from two different reactions which are protonation of CH3OH from the above two pathways possess the same structures, CH3OH2+. The value of kinetic energy release for the metastable decomposition CH2OH3+-> CH2OH+ + H-2 determined from the experiment is in good agreement with that from theoretical calculations. The transition state of above reaction were disscussed.

STUDY ON CYCLODEXTRIN AND ITS INCLUSION COMPLEXES - MOLECULAR MECHANICAL CALCULATION

We studied several inclusion complexes of beta-CD by means of molecular mechanical calculation. The inclusion process and the driving force were discussed, and the conclusion on stability agrees with the results of electrochemical experiments.

MEASUREMENT AND CALCULATION OF SPONTANEOUS EMISSION BRANCHING RATIOS, RELATIVE OSCILLATOR-STRENGTHS, TRANSITION-PROBABILITIES AND LEVEL LIFETIMES FOR ATOMIC URANIUM

We propose a laser induced sensitized fluorescence spectrometry for measuring the spontaneous emission branching ratios o?the transitions from the ten levels 5f36d7s7p-7M7, 5f36d7s7p-7L6, 5f37s27p-5K6, 5f26d27s2 - 5L7, 5f46d7s - 7L6, (17,070cm-1)-5L6, 5f26d27s2-5K6, 6d7s7p-7L5, 5f36d7s7p-7K5 and 5f26d27s2-5I5 to the ground state of atomic uranium (UI) for the first time. Their relative oscillator strengths have been measured by means of hollow cathode discharge (HCD) emission spectrometry. The radiative...

Numerical calculation of the response of the south China sea to typhoon imbudo

The response of the South China Sea (SCS) to Typhoon Imbudo was examined using POM model. The results indicated that SST decreased by 2-6 degrees C with a rightward-biased response as Typhoon Imbudo passed across the SCS. Due to a strong mixing process, the mixed layer (ML) depth deepened as much as 10-60 m and ML heat budget lost 824.78 W/m(2), which was OF dominated by the vertical mixing. By the response of upper ML heat transport, the temperature below the ML increased and oscillated near the inertial period. Furthermore, strong inertial currents were generated by the storm with the max currents up to 1.4 m/s in the upper ML.

Aminic nitrogen-bearing polydentate Schiff base compounds as corrosion inhibitors for iron in acidic media: A quantum chemical calculation

Quantum chemical calculations based on DFT method were performed on three polydentate Schiff base compounds (PSCs) used as corrosion inhibitors for iron in acid media to determine the relationship between the molecular structure of PSC and inhibition efficiency. The structural parameters, such as the frontier molecular orbital energy HOMO (highest occupied molecular orbital) and LUMO (lowest unoccupied molecular orbital), the charge distribution of the studied inhibitors, the absolute electronegativity (chi) values, and the fraction of electrons (Delta N) transfer from inhibitors to iron, were also calculated and correlated with inhibition efficiencies. The results showed that the inhibition efficiency of PSCs increased with the increase in E-HOMO and decrease in E-LUMO-E-HOMO; and the areas containing N atoms are most possible sites for bonding the metal iron surface by donating electrons to the metal. (C) 2007 Elsevier Ltd. All rights reserved.