Phase synchronism in organic single crystals with nonlinear susceptibility

FTIR, FT-Raman, UV–Visible spectra and quantum chemical calculations of allantoin molecule and its hydrogen bonded dimers

“…aromatic ring, exhibit strong second order non-linearity (2nd order molecular hyperpolarizability). This is because the system increases charge transfer through p-electron delocalization [80][81][82]. DFT calculations play a crucial role in designing NLO molecules and predicting their relevant properties like molecular dipole moments, polarizabilities and hyperpolarizabilities [83][84][85][86][87].…”

Influence of original and simulated microscopic units on SHG response in semiorganic NLO materials

“…The magnitude of the nonlinear susceptibility c NL (2u) is determined by the existence of charge transfer. 43 Conjugated molecules usually have a larger hyperpolarizability than nonconjugated ones, which indicates major donation of the delocalized p electrons. 44 Carbon is capable of forming many types of bonds due to its valence, such as, single, double and triple bonds.…”

Studies on acenaphthene (C12H10) single crystals grown by vertical Bridgman technique

“…However, such molecules absorb light in the visible region, and their colors are the main obstacle to application as frequency doublers. In addition to the requirements for linear and nonlinear optical properties, the crystal structure must belong to noncentrosymmetric class for the crystals to be SHG active [2].…”