Temperature-dependent Raman and infrared spectra of nucleosides. II?Cytidine

2001 ◽  
Vol 32 (9) ◽  
pp. 795-802 ◽  
Author(s):  
S. A. Lee ◽  
J. Li ◽  
A. Anderson ◽  
W. Smith ◽  
R. H. Griffey ◽  
...  
Keyword(s):  
Infrared Spectra ◽  
Temperature Dependent

scholarly journals Exploration of Free Energy Surface and Thermal Effects on Relative Population and Infrared Spectrum of the Be6B11− Fluxional Cluster

Materials ◽  
2020 ◽  
Vol 14 (1) ◽  
pp. 112
Author(s):  
Carlos Emiliano Buelna-Garcia ◽  
José Luis Cabellos ◽  
Jesus Manuel Quiroz-Castillo ◽  
Gerardo Martinez-Guajardo ◽  
Cesar Castillo-Quevedo ◽  
...  
Keyword(s):  
Free Energy ◽  
Infrared Spectrum ◽  
Infrared Spectra ◽  
Thermal Effects ◽  
Global Minimum ◽  
Energy Surface ◽  
Weighted Sums ◽  
Free Energy Surface ◽  
Temperature Dependent ◽  
Relative Population

The starting point to understanding cluster properties is the putative global minimum and all the nearby local energy minima; however, locating them is computationally expensive and difficult. The relative populations and spectroscopic properties that are a function of temperature can be approximately computed by employing statistical thermodynamics. Here, we investigate entropy-driven isomers distribution on Be6B11− clusters and the effect of temperature on their infrared spectroscopy and relative populations. We identify the vibration modes possessed by the cluster that significantly contribute to the zero-point energy. A couple of steps are considered for computing the temperature-dependent relative population: First, using a genetic algorithm coupled to density functional theory, we performed an extensive and systematic exploration of the potential/free energy surface of Be6B11− clusters to locate the putative global minimum and elucidate the low-energy structures. Second, the relative populations’ temperature effects are determined by considering the thermodynamic properties and Boltzmann factors. The temperature-dependent relative populations show that the entropies and temperature are essential for determining the global minimum. We compute the temperature-dependent total infrared spectra employing the Boltzmann factor weighted sums of each isomer’s infrared spectrum and find that at finite temperature, the total infrared spectrum is composed of an admixture of infrared spectra that corresponds to the spectra of the lowest-energy structure and its isomers located at higher energies. The methodology and results describe the thermal effects in the relative population and the infrared spectra.

Multilevel analysis of temperature dependent near-infrared spectra

Talanta ◽  
2015 ◽  
Vol 131 ◽  
pp. 170-174 ◽  
Author(s):  
Ruifeng Shan ◽  
Yue Zhao ◽  
Mengli Fan ◽  
Xiuwei Liu ◽  
Wensheng Cai ◽  
...  
Keyword(s):  
Multilevel Analysis ◽  
Infrared Spectra ◽  
Near Infrared ◽  
Temperature Dependent ◽  
Near Infrared Spectra

Temperature-dependent Raman and infrared spectra of nucleosides. III?deoxycytidine

2003 ◽  
Vol 34 (3) ◽  
pp. 183-191 ◽  
Author(s):  
J. Li ◽  
S. A. Lee ◽  
A. Anderson ◽  
L. Lettress ◽  
R. H. Griffey ◽  
...  
Keyword(s):  
Infrared Spectra ◽  
Temperature Dependent

Temperature-dependent infrared spectra of torsional vibrations in acetic acid

2005 ◽  
Vol 229 (2) ◽  
pp. 151-157 ◽  
Author(s):  
Daniel K. Havey ◽  
Karl J. Feierabend ◽  
Joshua C. Black ◽  
Veronica Vaida
Keyword(s):  
Acetic Acid ◽  
Infrared Spectra ◽  
Torsional Vibrations ◽  
Temperature Dependent

RAMAN AND INFRARED STUDY OF PHASE TRANSFORMATION IN CRYSTALLINE HYDROGEN IODIDE AND DEUTERIUM IODIDE HI AND DI

1989 ◽  
Vol 03 (11) ◽  
pp. 1671-1679 ◽  
Author(s):  
W.S. TSE ◽  
C.S. FANG ◽  
A. ANDERSON ◽  
B.H. TORRIE
Keyword(s):  
Phase Transformation ◽  
Phase Transitions ◽  
Melting Point ◽  
Infrared Spectra ◽  
Hydrogen Iodide ◽  
Temperature Dependent ◽  
Two Phase ◽  
Infrared Study ◽  
X Ray ◽  
Temperature Range

Raman and infrared spectra of polycrystalline HI and DI in the region of lattice and internal modes for all three phases have been recorded over the temperature range 18 K to the melting point. The temperature dependent Raman and infrared results are consistent with the X-ray and neutron work that two phase transitions occur at HI and DI involving reorientation of the HI and DI molecules as a whole.

Sign in / Sign up

Export Citation Format

Share Document