Li Jin-Feng, Yin Bing
College of Chemistry & Chemical Engineering, Shaanxi Key Laboratory of Chemical Reaction Engineering, Yan'an University, Yan'an 716000, China.
Key Laboratory of Synthetic and Natural Functional Molecule of the Ministry of Education, College of Chemistry and Materials Science, Northwest University, Xi'an 710127, P. R. China.
J Phys Chem A. 2021 Apr 29;125(16):3378-3386. doi: 10.1021/acs.jpca.1c01623. Epub 2021 Apr 15.
Via combined and DFT calculations, 16 [Mg(OCN)] and [Mg(SCN)] isomers are studied to explore their potentials as superhalogens. The results of high-level OVGF calculations verify that these systems are superhalogen anions due to their high VDE values which lie within 6.74-7.04 eV and 5.73-6.27 eV for [Mg(OCN)] and [Mg(SCN)], respectively. The results of low-cost methods, either or DFT, are generally consistent with those of OVGF, and some of them demonstrate promising accuracy. The best performance of low-cost methods comes from (HF+MP2)/2, which represents the average value of the MP2 and HF results. In the aspect of DFT, five functionals (CAM-B3LYP, ωB97X-D3, M06, M06-2X, and B2PLYP) provide the most accurate results when compared to OVGF. Thus, these low-cost methods could be used to calculate the VDE value of the future systems of larger size. Useful information about the VDEs of [Mg(OCN)] and [Mg(SCN)] could be obtained from the analysis of the extra electron density and HOMO as well as spin density.
