08_static calculation method - Yiwei666/08_computional-chemistry-learning-materials- GitHub Wiki
1. Stabilization mechanism of arsenic-sulfide slag by density functional theory calculation of arsenic-sulfide clusters
- Computational details
The initial configuration searches for the (As2S2)n, (As2S3)n and (As2S5)n (n = 1–8) clusters were based on two steps. Firstly, By the ABCluster 2.0 global search technique combined with the GFN1-xTB, more than 5000 isomers structure for (As2S2)n, (As2S3)n and (As2S5)n (n = 1–8) clusters were predicted (Grimme and Bannwarth, 2016, Grimme et al., 2017, Zhang and Dolg, 2015, Zhang and Dolg, 2016). Secondly, the first three minimum structure were optimized using B3LYP functional with the all-electron small basis sets (def2SVP) by Gaussian 09 package (Frisch et al., 2013, Stephens et al., 1994). Vibrational frequency calculations were carried out at the same level to check the local minima structure on the potential energy surface else. Meanwhile, spin multiplicity is fully considered during the geometric optimization process. After completion of initial configuration searches work, we selected B3LYP functional with the all-electron def2TZVP basis sets to refine the single-point energy calculation. Implicit solvent model is assessed to correct potential energy surface and all-electron properties caused by solvent effect in all process. Thirdly, the wave function analysis including the structural parameter was carried out by Multiwfn 3.5 to realize orbital information and electronic properties, and the Raman spectrum was calculated (Lu and Chen, 2012a). To verify the accuracy of the optimization method, we employed different functionals and basic sets (e.g., the theoretical binding energy, bond length and vibration frequency of As2 dimer and S2 dimer), and the results were compared to the measured experiments data, as shown in Table S1. Electron Localization Function (ELF) was calculated while we choose the isosurface value is 0.7 for As16S16 cluster, As16S24 cluster and As16S40 cluster.