scholarly journals First Hyperpolarizability of Water at the Air-Vapor Interface: A QM/MM Study Questions Standard Experimental Approximations

2021 ◽  
Author(s):  
Guillaume Le Breton ◽  
Oriane Bonhomme ◽  
Pierre-Francois Brevet ◽  
Emmanuel Benichou ◽  
Claire Loison
Keyword(s):  
Second Harmonic Generation ◽  
Harmonic Generation ◽  
Molecular Level ◽  
Second Harmonic ◽  
First Hyperpolarizability ◽  
Vapor Interface ◽  
Unique Approach

Surface Second-harmonic generation (S-SHG) experiments provide a unique approach to probe interfaces. One important issue for S-SHG is how to interpret the S-SHG intensities at the molecular level. Established frameworks...

scholarly journals Dynamic Structural Effects on the Second-Harmonic Generation of Tryptophane-Rich Peptides and Gramicidin A

2020 ◽  
Author(s):  
Jakob Seibert ◽  
Benoît CHAMPAGNE ◽  
Stefan Grimme ◽  
Marc de Wergifosse
Keyword(s):  
Second Harmonic Generation ◽  
Harmonic Generation ◽  
Density Functional ◽  
Second Harmonic ◽  
Tight Binding ◽  
Computational Cost ◽  
Conformational Space ◽  
First Hyperpolarizability ◽  
Structure Property ◽  
Tryptophan Residues

<div>Chains of amino acids can model endogenous biotags for applications in second harmonic imaging microscopy. Such structures are inherently flexible which may strongly affect their structure-property relationship. Here, we explore quantum-mechanically the conformational space of a set of relatively large tryptophan-rich model peptides studied experimentally by Duboisset et al. [JPC B 2014 118]. This has become feasible because of the recently proposed meta-dynamics method based on efficient tight-binding (TB) quantum chemical calculations. The TB version of the simplified time-dependent density functional theory (sTD-DFT-xTB) method is used to evaluate the first hyperpolarizability. These new tools enable us to calculate nonlinear optical properties for systems with several thousand atoms and/or to screen large structure ensembles. First, we show that the first hyperpolarizability of these systems is dominated by the indole chromophore in the tryptophan residues. Their relative orientation mostly determines the global β tensor and affects the static first hyperpolarizability response drastically. The results underline the importance of finding low-energy conformers for modeling the first hyperpolarizabilities of flexible molecules. Additionally, we compare calculated and extrapolated experimental static first hyperpolarizabilities. <br></div><div>We conclude that the sTD-DFT-xTB method is capable of providing reliable second-harmonic generation values for tryptophan-rich systems at a fraction of the computational cost of the commonly used TD-DFT/TD-HF levels of theory.</div>

Surface area-dependent second harmonic generation from silver nanorods

2016 ◽  
Vol 18 (33) ◽  
pp. 23215-23219 ◽  
Author(s):  
Hoang Minh Ngo ◽  
Thanh Tuyen Luong ◽  
Isabelle Ledoux-Rak
Keyword(s):  
Second Harmonic Generation ◽  
Surface Area ◽  
Harmonic Generation ◽  
Second Harmonic ◽  
First Hyperpolarizability ◽  
Silver Nanorods ◽  
First Time

We have evidenced strong first hyperpolarizabilities in silver nanorods (AgNRs) for the first time. The first hyperpolarizability β values linearly depend on the surface area of AgNRs.

Hyper-Rayleigh Scattering (Hrs) In Isotropic Media

1993 ◽  
Vol 328 ◽  
Author(s):  
Eric Hendrickx ◽  
Thierry Verbiest ◽  
Koen Clays ◽  
Celest Samyn ◽  
Andre Persoons
Keyword(s):  
Electric Field ◽  
Second Harmonic Generation ◽  
Harmonic Generation ◽  
Rayleigh Scattering ◽  
Second Harmonic ◽  
Accurate Determination ◽  
First Hyperpolarizability ◽  
Isotropic Media ◽  
Set Up

ABSTRACTIn this paper some of the more important Hyper Rayleigh Scattering (HRS) Measurements performed in our laboratory are reviewed. The results of experiments conducted on polymers, the protein Bacteriorhodopsin, retinal derivatives and octopoles are presented. Basic HRS theory, along with a brief description of the HRS set-up, is also included.We demonstrate that the experimental simplicity of HRS allows for an accurate determination of the first hyperpolarizability of molecules that could not have been measured by the more traditional Electric Field Induced Second Harmonic Generation (EFISHG) technique.

Optimization of second harmonic generation of gold nanospheres and nanorods in aqueous solution: the dominant role of surface area

2016 ◽  
Vol 18 (4) ◽  
pp. 3352-3356 ◽  
Author(s):  
Hoang Minh Ngo ◽  
Phuong Phong Nguyen ◽  
Isabelle Ledoux-Rak
Keyword(s):  
Aqueous Solution ◽  
Gold Nanoparticles ◽  
Second Harmonic Generation ◽  
Surface Area ◽  
Harmonic Generation ◽  
Second Harmonic ◽  
Dominant Role ◽  
First Hyperpolarizability ◽  
Gold Nanospheres

Gold nanoparticles display exceptionally strong β values. We demonstrated that the first hyperpolarizability (β) strongly depends on surface area of gold nanoparticles.

Second harmonic generation from the novel polar polymorph α/β-BaTeMo2O9 phases

RSC Advances ◽  
2015 ◽  
Vol 5 (87) ◽  
pp. 70992-71001 ◽  
Author(s):  
A. H. Reshak
Keyword(s):  
Second Harmonic Generation ◽  
Harmonic Generation ◽  
Second Harmonic ◽  
The Novel ◽  
First Hyperpolarizability

The second harmonic generation (SHG) and the first hyperpolarizability (βijk) of β-BaTeMo2O9 and α-BaTeMo2O9 phases have been calculated.

scholarly journals Dynamic Structural Effects on the Second-Harmonic Generation of Tryptophane-Rich Peptides and Gramicidin A

2020 ◽  
Author(s):  
Jakob Seibert ◽  
Benoît CHAMPAGNE ◽  
Stefan Grimme ◽  
Marc de Wergifosse
Keyword(s):  
Second Harmonic Generation ◽  
Harmonic Generation ◽  
Density Functional ◽  
Second Harmonic ◽  
Tight Binding ◽  
Computational Cost ◽  
Conformational Space ◽  
First Hyperpolarizability ◽  
Structure Property ◽  
Tryptophan Residues

<div>Chains of amino acids can model endogenous biotags for applications in second harmonic imaging microscopy. Such structures are inherently flexible which may strongly affect their structure-property relationship. Here, we explore quantum-mechanically the conformational space of a set of relatively large tryptophan-rich model peptides studied experimentally by Duboisset et al. [JPC B 2014 118]. This has become feasible because of the recently proposed meta-dynamics method based on efficient tight-binding (TB) quantum chemical calculations. The TB version of the simplified time-dependent density functional theory (sTD-DFT-xTB) method is used to evaluate the first hyperpolarizability. These new tools enable us to calculate nonlinear optical properties for systems with several thousand atoms and/or to screen large structure ensembles. First, we show that the first hyperpolarizability of these systems is dominated by the indole chromophore in the tryptophan residues. Their relative orientation mostly determines the global β tensor and affects the static first hyperpolarizability response drastically. The results underline the importance of finding low-energy conformers for modeling the first hyperpolarizabilities of flexible molecules. Additionally, we compare calculated and extrapolated experimental static first hyperpolarizabilities. <br></div><div>We conclude that the sTD-DFT-xTB method is capable of providing reliable second-harmonic generation values for tryptophan-rich systems at a fraction of the computational cost of the commonly used TD-DFT/TD-HF levels of theory.</div>

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