14 N NQR Study of Urea and Thiourea

TLDR: Based on the density functional theory (DFT), employing Beckes three-parameter hybrid functional combined with Lee-Yang-Parr correlation functional (B3LYP), with 6-311++G(d,p) basis set, Wang et al. as discussed by the authors have obtained the quantum chemical calculations by using Gaussian 09.

Abstract: Nuclear quadrupole resonance (NQR) is a newly developed branch of radio frequency (RF) spectroscopic technique, allowing the detection of many substances containing quadrupole nuclei, such as 14N and 35Cl, widely existing in explosives and narcotics respectively. In this paper, we focus on the research of its detection mechanism for 14N in urea and thiourea. Based on the Density Functional Theory (DFT), employing Beckes three-parameter hybrid functional combined with Lee-Yang-Parr correlation functional (B3LYP), with 6-311++G(d,p) basis set, we have obtained the quantum chemical calculations by using Gaussian 09. Furthermore, experimental results and some discussions related are also presented. At last, we find that the absolute values of relative errors of NQR frequencies are all less than 2%, which indicates that this study is reasonable.