The molecular dynamics method is used to investigate the interaction between one-six nitrate anions and water clusters absorbing six ozone molecules. The infrared（IR） absorption and reflection spectra are reshaped s...The molecular dynamics method is used to investigate the interaction between one-six nitrate anions and water clusters absorbing six ozone molecules. The infrared（IR） absorption and reflection spectra are reshaped significantly, and new peaks appear at Raman spectra due to the addition of ozone and nitrate anions to the disperse water system. After ozone and nitrate anions are captured, the average（in frequency） IR reflection coefficient of the water disperse system increased drastically and the absorption coefficient fell.展开更多
The interaction of water clusters that adsorbed methane molecules with infrared radiation is studied by molecular dynamics. The presence of methane molecules in the disperse water system leads to an increase in absorp...The interaction of water clusters that adsorbed methane molecules with infrared radiation is studied by molecular dynamics. The presence of methane molecules in the disperse water system leads to an increase in absorption and emission of infrared radiation and a strong depletion of the Raman spectrum. In this case, the reflection coefficient of a monochromatic plane electromagnetic wave increases and its frequency spectrum significantly changes. The comparison of experimental data for similar characteristics of water, methane, or their mixtures is presented.展开更多
The interaction of （Br-）i（H2O）50-i, 0 ≤ i ≤ 6 clusters with oxygen and ozone molecules is investigated by the method of molecular dynamics simulation. The ozone molecules as well as the bromine ions do not leave...The interaction of （Br-）i（H2O）50-i, 0 ≤ i ≤ 6 clusters with oxygen and ozone molecules is investigated by the method of molecular dynamics simulation. The ozone molecules as well as the bromine ions do not leave the cluster during the calculation of 25 ps. The ability of the cluster containing molecular oxygen to absorb the infrared （IR） radiation is reduced in the frequency range of 0≤ w ≤ 3500 cm-1 when the number of the bromine ions in the cluster grows. The intensity of the Raman spectrum is not changed significantly when the Brions are added to the ozone- containing system. The power of the emitted IR radiation is increased when the number of bromine ions grows in the oxygen-containing system. The data obtained in this study on the IR and the Raman spectra of the water clusters that contain ozone, oxygen, and Br- can be used to develop an investigation of the mechanisms of ozone depletion.展开更多
Body-centered tetragonal C4 （bct C4） is a new form of crystalline spa carbon, which is found to be transparent, dynamically stable at zero pressure and more stable than graphite beyond 18.6 GPa. Symmetry analysis of...Body-centered tetragonal C4 （bct C4） is a new form of crystalline spa carbon, which is found to be transparent, dynamically stable at zero pressure and more stable than graphite beyond 18.6 GPa. Symmetry analysis of the vibrational modes of bct C4 at Brillouin zone center is performed, Raman and infrared active modes are identified. The analysis results show that, different from cubic diamond and hexagonal diamond, there is an infrared active mode in bct C4. Based on first-principle method within the local density approximation, vibrational frequencies, Born effective charge tensors, and infrared absorption intensity of bct C4 are obtained. The vibrational modes of bct C4 are presented and compared with those of cubic diamond and hexagonal diamond in detail展开更多
Under high pressure, a cagelike diamondoid nitrogen structure was lately discovered by first-principles structure researches. This newly proposed structure is very unique and has not been observed in any other element...Under high pressure, a cagelike diamondoid nitrogen structure was lately discovered by first-principles structure researches. This newly proposed structure is very unique and has not been observed in any other element. Using densityfunctional calculations, we study the pressure effect on its vibrational properties. The Born effective charges are calculated, and the resulting LO-TO splittings of certain infrared active modes are beyond 20 cm-1. We depict the F-point vibrational modes and find the breathing mode, rotational mode, and shearing mode. Frequencies of all the optical modes increase with pressure increasing. Moreover, the relation between the breathing mode frequency and the nitrogen cage diameter is discussed in detail. Our calculation results give a deeper insight into the vibrational properties of the cagelike diamondoid nitrogen.展开更多
文摘The molecular dynamics method is used to investigate the interaction between one-six nitrate anions and water clusters absorbing six ozone molecules. The infrared（IR） absorption and reflection spectra are reshaped significantly, and new peaks appear at Raman spectra due to the addition of ozone and nitrate anions to the disperse water system. After ozone and nitrate anions are captured, the average（in frequency） IR reflection coefficient of the water disperse system increased drastically and the absorption coefficient fell.
文摘The interaction of water clusters that adsorbed methane molecules with infrared radiation is studied by molecular dynamics. The presence of methane molecules in the disperse water system leads to an increase in absorption and emission of infrared radiation and a strong depletion of the Raman spectrum. In this case, the reflection coefficient of a monochromatic plane electromagnetic wave increases and its frequency spectrum significantly changes. The comparison of experimental data for similar characteristics of water, methane, or their mixtures is presented.
基金Project supported by the Russian Foundation of Basic Research (Grant No. 08-08-00136-a)
文摘The interaction of （Br-）i（H2O）50-i, 0 ≤ i ≤ 6 clusters with oxygen and ozone molecules is investigated by the method of molecular dynamics simulation. The ozone molecules as well as the bromine ions do not leave the cluster during the calculation of 25 ps. The ability of the cluster containing molecular oxygen to absorb the infrared （IR） radiation is reduced in the frequency range of 0≤ w ≤ 3500 cm-1 when the number of the bromine ions in the cluster grows. The intensity of the Raman spectrum is not changed significantly when the Brions are added to the ozone- containing system. The power of the emitted IR radiation is increased when the number of bromine ions grows in the oxygen-containing system. The data obtained in this study on the IR and the Raman spectra of the water clusters that contain ozone, oxygen, and Br- can be used to develop an investigation of the mechanisms of ozone depletion.
文摘Body-centered tetragonal C4 （bct C4） is a new form of crystalline spa carbon, which is found to be transparent, dynamically stable at zero pressure and more stable than graphite beyond 18.6 GPa. Symmetry analysis of the vibrational modes of bct C4 at Brillouin zone center is performed, Raman and infrared active modes are identified. The analysis results show that, different from cubic diamond and hexagonal diamond, there is an infrared active mode in bct C4. Based on first-principle method within the local density approximation, vibrational frequencies, Born effective charge tensors, and infrared absorption intensity of bct C4 are obtained. The vibrational modes of bct C4 are presented and compared with those of cubic diamond and hexagonal diamond in detail
文摘Under high pressure, a cagelike diamondoid nitrogen structure was lately discovered by first-principles structure researches. This newly proposed structure is very unique and has not been observed in any other element. Using densityfunctional calculations, we study the pressure effect on its vibrational properties. The Born effective charges are calculated, and the resulting LO-TO splittings of certain infrared active modes are beyond 20 cm-1. We depict the F-point vibrational modes and find the breathing mode, rotational mode, and shearing mode. Frequencies of all the optical modes increase with pressure increasing. Moreover, the relation between the breathing mode frequency and the nitrogen cage diameter is discussed in detail. Our calculation results give a deeper insight into the vibrational properties of the cagelike diamondoid nitrogen.
