Vibrational energy transfer of the amide I mode of N-methylacetamide (NMA) is studied theoretically using the vibrational configuration interaction method. A quartic force field of NMA is constructed at the B3LYP/6-31G+(d) level of theory and its accuracy is checked by comparing the resulting anharmonic frequencies with available theoretical and experimental values. Quantum dynamics calculation...

Over the past decade, we have developed a spectroscopic approach to measure electric fields inside matter with high spatial (<1 Å) and field (<1 MV/cm) resolution. The approach hinges on exploiting a physical phenomenon known as the vibrational Stark effect (VSE), which ultimately provides a direct mapping between observed vibrational frequencies and electric fields. Therefore, the frequency of...

Vibrational sum-frequency generation (vSFG) measurements in the frequency and time domains reveal that the interfacial hydrogen bonded OH stretch at the water/calcium fluoride interface is composed of two populations oriented oppositely. The time-resolved vSFG free-induction decay suggested that, whereas the strongly hydrogen bonded OH vibrational stretches, centered near 3140 ± 11 cm-1, are or...

Vibrational lifetimes of hydrogen and deuterium related bending modes in semiconductors are measured by transient bleaching spectroscopy and high-resolution infrared absorption spectroscopy. We find that the vibrational lifetimes follow a universal frequency-gap law; i.e., the decay time increases exponentially with increasing decay order, with values ranging from 1 ps for a one-phonon process ...

Detection of ethyl and methyl centralites in gunshot residues is important in forensic science due to their limited contamination from environmental sources compared to other organic residues. However, the vibrational frequencies of centralites are little explored and their frequency assignments are incomplete. Herein, we investigated vibrational frequencies of centralites based on Density func...

– Glasses have an excess number of low-frequency vibrational modes in comparison with most crystalline solids. We show that such a feature necessarily occurs in solids with low coordination. In particular, we analyze the density D(ω) of normal-mode frequencies ω and the nature of the low-frequency normal modes of a recently simulated system [1], comprised of weakly compressed spheres at zero te...

Connectedness and applied stress strongly affect elasticity in solids. In various amorphous materials, mechanical stability can be lost either by reducing connectedness or by increasing pressure. We present an effective medium theory of elasticity that extends previous approaches by incorporating the effect of compression, of amplitude e, allowing one to describe quantitative features of sound ...

S. JEYAKUMARI, V. CHINNATHAMBI Department of Physics, Sri K.G.S. Arts College, Srivaikuntam 628 619, Tamilnadu, India., S. RAJASEKAR School of Physics, Bharathidasan University, Tiruchirapalli 620 024, Tamilnadu, India. [email protected], and M.A.F. SANJUAN Departamento de F́ısica, Universidad Rey Juan Carlos, Tulipán s/n, 28933 Móstoles, Madrid, Spain. [email protected] Abstract We ...

The interaction of dopamine and cysteine for formation of 5-S-cysteinyldopamine are investigated at theHartree-Fock level theory. The structural and vibrational properties of 5-S-cysteinyldopamine are studiedat level of HF/6-31G*.Interaction energy ( AE) is calculated -771.6923 Kcal/mol Rotational energy andthermodynamic parameters around two bond have been determined using HF/3-21G. Changes of...

The local elasticity of glasses is known to be inhomogeneous on a microscopic scale compared to that of crystalline materials. Their vibrational spectrum strongly deviates from that expected from Debye's elasticity theory: The density of states deviates from Debye's law, the sound velocity shows a negative dispersion in the boson-peak frequency regime and there is a strong increase of the sound...