Effect of the crystalline environment on the third-order nonlinear optical properties of L-arginine phosphate monohydrate: a theoretical study.
A supermolecular approach combined with an iterative electrostatic scheme was employed to investigate the nonlinear optical properties of the hybrid L-arginine phosphate monohydrate crystal, the procedure being aided by DFT calculations. The supermolecular scheme basically treated the molecules surrounding the unit cell as point charges; this approximation results in rapid convergence, making it a feasible method. DFT functionals of different flavors were considered: B3LYP, B2PLYP, CAM-B3LYP, ωB97, and M06HF, utilizing the 6-311 + G(d) basis set. All functionals gave sufficiently accurate values for the dipole moment (μ) with respect to the experimental value 32(2) D. For the average linear polarizability ([Formula: see text]) and the total first hyperpolarizability (βtot), good agreement was observed between the DFT-calculated values and MP2-derived results reported in the literature. For the second hyperpolarizability, both static and dynamic regimes were considered. The point-charge embedding approach led to an attenuation of the second hyperpolarizability γ for all frequencies considered. Excitations of γ were not observed for frequencies smaller than 0.1 a.u. For the second hyperpolarizability (both static and dynamic), computational results showed that L-arginine phosphate monohydrate exhibits a large nonlinear optical effect, which implies the occurrence of microscopic third-order NLO behavior.
Campus Henrique Santillo, Universidade Estadual de Goiás, 75.132-903, Anápolis, GO, Brazil. valverde@ueg.br.|Universidade Paulista (UNIP), 74845-090, Goiânia, GO, Brazil. valverde@ueg.br.
Clodoaldo
C
Valverde
Campus Henrique Santillo, Universidade Estadual de Goiás, 75.132-903, Anápolis, GO, Brazil.
Rosemberg F N
RF
Rodrigues
Laboratório de Estrutura Eletrônica e Dinâmica Molecular (LEEDMOL), Universidade de Brasília, Campus Darcy Ribeiro, Brasília, DF, Brazil.
Daniel F S
DF
Machado
Instituto de Física, Universidade Federal de Goiás, 74001-970, Goiânia, GO, Brazil.|Departamento de Física, Universidade Federal da Paraíba, 58.051-970, João Pessoa, PB, Brazil.
Basílio
B
Baseia
Laboratório de Estrutura Eletrônica e Dinâmica Molecular (LEEDMOL), Universidade de Brasília, Campus Darcy Ribeiro, Brasília, DF, Brazil. heibbe@unb.br.
Heibbe C B
HC
de Oliveira
Dipole moment; Electrostatic effects; L-Arginine phosphate monohydrate; NLO; Second hyperpolarizability