Related Experiment Video
Updated: Feb 27, 2026

Hyperspectral Imaging as a Tool to Study Optical Anisotropy in Lanthanide-Based Molecular Single Crystals
Published on: April 14, 2020
Two haloid borate crystals with large nonlinear optical response
1New Technologies - Research Centre, University of West Bohemia, Univerzitni 8, 306 14 Pilsen, Czech Republic. maalidph@yahoo.co.uk.
Abstract:
The photophysical properties of the noncentrosymmetric haloid borates K3B6O10X (X = Cl or Br) are calculated using density functional theory within the recently modified Becke-Johnson potential. The calculated electronic band structure reveals that the theoretical direct band gaps, 5.21 eV (K3B6O10Cl) and 4.85 eV (K3B6O10Br), are in good agreement with the previous calculation for K3B6O10Cl (5.16 eV) and experimental data for K3B6O10Br (4.86 eV). The calculated absorption coefficients, refractive indices, and birefringence are also in good agreement with the experimental data. The calculated nonzero second harmonic generation (SHG) coefficients, d33, d22 (= -d21), and d15(= d32 = d31), show good agreement with the experimental values. Furthermore, we have obtained the microscopic first hyperpolarizability for the dominant tensor component of the SHG.
Related Concept Videos
Hybridization of Atomic Orbitals I
Hydroboration-Oxidation of Alkenes
VSEPR Theory and the Effect of Lone Pairs
Crystal Field Theory - Octahedral Complexes
To explain the observed behavior of transition metal complexes (such as colors), a model involving electrostatic interactions between the electrons from the ligands and the electrons in the unhybridized d orbitals of the central metal atom has been developed. This electrostatic model is crystal field theory (CFT). It helps to understand, interpret, and predict the colors, magnetic behavior, and some structures of coordination compounds of transition metals.
CFT focuses on...
Regioselectivity and Stereochemistry of Hydroboration
Hydroboration proceeds in a concerted fashion with the attack of borane on the π bond, giving a cyclic four-centered transition state. The –BH2 group is bonded to the less substituted carbon and –H to the more substituted carbon. The concerted nature requires the simultaneous addition of –H and –BH2 across the same face of the alkene giving syn stereochemistry.
Ionic Crystal Structures
Most monatomic ions behave as charged spheres, and their attraction for ions of opposite charge is the same in every direction. Consequently, stable structures for ionic compounds result (1) when ions of one charge are surrounded by as many ions as possible of the opposite...

