研究目的
To theoretically compute the anharmonic infrared spectrum of individual C60 and C70 fullerenes under hydrostatic pressure using atomistic simulations.
研究成果
The infrared spectroscopic responses exhibit linear variations relative to the isolated reference cases. The pressure coefficients generally show positive values and agree reasonably with existing measurements. For C70, one soft mode displays a negative pressure coefficient, interpreted as a direct manifestation of anharmonicities.
研究不足
The study focuses on physical effects rather than those involving possibly complex chemistry. The model ignores the possible chemistry between the fullerene and the fluid, and only focuses on the physical effects of hydrostatic pressure.
1：Experimental Design and Method Selection:
The study employs a tight-binding model for the fullerenes and a simple particle-based pressure-transmitting fluid to determine the structural and vibrational properties at room temperature and up to 20 GPa.
2：Sample Selection and Data Sources:
The samples used are individual C60 and C70 fullerenes embedded into an explicit pressure-transmitting fluid of particles.
3：List of Experimental Equipment and Materials:
The interaction among fluid particles is modeled using a purely repulsive pair potential with finite range. The TB model for carbon atoms was used with parameters adjusted for vibrational spectroscopic features.
4：Experimental Procedures and Operational Workflow:
Molecular dynamics at constant temperature and fixed volume were carried out to generate series of initial conditions in the canonical ensemble. The Nosé–Hoover method was employed to impose the temperature of 300 K.
5：Data Analysis Methods:
The absorption intensity at excitation frequency is calculated from the line shape function and the refraction coefficient. The line shape is the Fourier transform of the dipole moment time autocorrelation function.
独家科研数据包，助您复现前沿成果，加速创新突破
获取完整内容
