Static hyperpolarizability of the van der Waals complex CH(4)-N(2)
Yulia N Kalugina1, Mikhail A Buldakov, Victor N Cherepanov
1Tomsk State University, 36, Lenin Avenue, 634050 Tomsk, Russia. kalugina@phys.tsu.ru
Journal of Computational Chemistry
|August 21, 2012
Summary
We calculated the static first hyperpolarizability of the methane-nitrogen (CH(4)-N(2)) van der Waals complex. Stable configurations showed minimal hyperpolarizability changes, with decreased hyper-Rayleigh scattering intensity.
Area of Science:
- Computational chemistry
- Quantum chemistry
- Molecular interactions
Background:
- Van der Waals complexes are crucial for understanding intermolecular forces.
- Hyperpolarizability is a key property in nonlinear optics and molecular response theory.
Purpose of the Study:
- To calculate the static first hyperpolarizability of the CH(4)-N(2) van der Waals complex.
- To compare theoretical calculations with long-range approximations.
- To analyze the impact of complex formation on hyper-Rayleigh scattering.
Main Methods:
- Ab initio calculations at the Coupled Cluster Singles Doubles with Perturbative Triples (CCSD(T)) level.
- Utilized the augmented correlation-consistent triple-zeta (aug-cc-pVTZ) basis set.
- Applied basis set superposition error correction for intermolecular separations (R = 6-40 a(0)).
Main Results:
- Long-range classical approximation (up to R(-6)) agrees well with ab initio results for R > 11 a(0).
- First hyperpolarizability invariants showed negligible changes (<0.1%) for stable CH(4)-N(2) configurations.
- Hyper-Rayleigh scattering intensity and depolarization degree decreased by ~10% upon complex formation.
Conclusions:
- The study validates computational methods for predicting hyperpolarizability in van der Waals complexes.
- Formation of the CH(4)-N(2) complex significantly influences its nonlinear optical properties.
- Results provide insights into intermolecular effects on molecular polarizability.
Related Concept Videos
02:42Valence Bond Theory
Coordination compounds and complexes exhibit different colors, geometries, and magnetic behavior, depending on the metal atom/ion and ligands from which they are composed. In an attempt to explain the bonding and structure of coordination complexes, Linus Pauling proposed the valence bond theory, or VBT, using the concepts of hybridization and the overlapping of the atomic orbitals. According to VBT, the central metal atom or ion (Lewis acid) hybridizes to provide empty orbitals of suitable...
02:45Valence Bond Theory
Overview of Valence Bond Theory
01:24Van der Waals Interactions
Atoms and molecules interact with each other through intermolecular forces. These electrostatic forces arise from attractive or repulsive interactions between particles with permanent, partial, or temporary charges. The intermolecular forces between neutral atoms and molecules are ion–dipole, dipole–dipole, and dispersion forces, collectively known as van der Waals forces.
01:10Van der Waals Equation
The ideal gas law is an approximation that works well at high temperatures and low pressures. The van der Waals equation of state (named after the Dutch physicist Johannes van der Waals, 1837−1923) improves it by considering two factors.
First, the attractive forces between molecules, which are stronger at higher densities and reduce the pressure, are considered by adding to the pressure a term equal to the square of the molar density multiplied by a positive coefficient a. Second, the volume...
First, the attractive forces between molecules, which are stronger at higher densities and reduce the pressure, are considered by adding to the pressure a term equal to the square of the molar density multiplied by a positive coefficient a. Second, the volume...
02:48Bond Polarity, Dipole Moment, and Percent Ionic Character
Bond Polarity
01:26The Van der Waals Equation
The ideal gas law is based on two simplifying assumptions: first, that there are no intermolecular attractions between gas molecules, and second, that the volume occupied by the molecules themselves is negligible compared with the volume of the container. However, these assumptions don't hold up under all conditions - specifically, at high pressures and low temperatures, as gas tends to deviate from ideal gas behavior.The van der Waals equation is an enhanced version of the ideal gas law,...