Calculation of anharmonic vibrational spectroscopy of small biological molecules

The Prediction of Thermo Physical, Vibrational Spectroscopy, Chemical Reactivity, Biological Properties of Morpholinium Borate, Phosphate, Chloride and Bromide Ionic Liquid: A DFT Study

In the light of computational chemistry, based on morpholinium cation-based Ionic Liquid, their different types of physical, chemical, and biological properties is highlighted. The physical properties are evaluated through the Density Functional Theory (DFT) of Molecular Mechanics and also examine the chemical and biological properties. The difference between Highest Occupied Molecular Orbital ...

On the benefits of localized modes in anharmonic vibrational calculations for small molecules.

Anharmonic vibrational calculations can already be computationally demanding for relatively small molecules. The main bottlenecks lie in the construction of the potential energy surface and in the size of the excitation space in the vibrational configuration interaction (VCI) calculations. To address these challenges, we use localized-mode coordinates to construct potential energy surfaces and ...

Degenerate perturbation theory corrections for the vibrational self-consistent field approximation: Method and applications

A new algorithm for computing anharmonic vibrational states for polyatomic molecules is proposed. The algorithm starts with the vibrational self-consistent field ~VSCF! method and uses degenerate perturbation theory to correct for effects of correlation between different vibrational modes. The algorithm is developed in a version that computes the anharmonic vibrational spectroscopy directly fro...

Progress towards the Accurate Calculation of Anharmonic Vibrational States of Flux- Ional Molecules and Clusters without a Potential Energy Surface

Comparison of algorithms for the calculation of molecular vibrational level densities.

Level densities of vibrational degrees of freedom are calculated numerically with formulas based on the inversion of the canonical vibrational partition function. The calculated level densities are compared with other approximate equations from literature and with the exact Beyer-Swinehart values, for which a simplified but equivalent version is given. All approximate equations agree at high ex...