|
|
本帖最后由 沉迷计算 于 2025-12-7 18:54 编辑
最近在用VASPsol计算CeO2隐式溶剂化,发现无论使用水还是其他溶液的介电常数,前几步SOL的值都过大,整个体系很难收敛。文献中也提到VASPsol计算CeO2会存在问题,我之前考虑过可能是+U的问题;Ce的赝势选择问题;4f电子的问题等一系列Ce的独特性质的原因,但是无论加不加U,选什么赝势,涉及CeO2的计算都不收敛。而与CeO2相似的SmO2/Fe3O4/Gd2O3/PrO2/PuO2/SmO2/TbO2/ThO2/UO2的溶剂化计算都没有问题,所以想请教一下是什么特殊原因导致了VASPsol计算CeO2的难收敛,谢谢!
(后边列出了CeO2和其他体系的输出对比以及相关文献)
CeO2的输出前几步,能看出SOL数值过大:
非CeO2体系的输出,SOL数值稳定,可以正常收敛:
文献指出CeO2溶剂化存在问题:
(ACS Catal. 2022, 12, 16, 10222–10234)
The effects of solvation by water were modeled implicitly by treating the solvent as a dielectric continuum. While VASPsol [url=](87,88)[/url] has been popularly used to study solvation effects for a variety of molecules and extended structures, self-consistent field (SCF) cycles failed to converge for the CeO2 facets. Indeed, there has been no study reporting the application of VASPsol to modeling solvation of CeO2 surfaces, to the best of our knowledge. Therefore, VASPsol was applied only to isolated molecular species at default settings.
(ACS Catal. 2022, 12, 16, 10222–10234)
Attempts to include solvent effects through implicit solvents failed owing to well-known instabilities in VASPsol (67−69) for cerium oxides. (70) We therefore attempted to obtain solvation energies by performing single-point computations using the SCCS model (71) implemented into CP2K (version: 9.1). (72) However, we were unable to converge the wave function. Similarly, attempts to obtain solvation energies using CANDLE (73) and GLSSA13 (73−75) implemented into jDFTx (version: 1.7.0) (76) failed owing to severe instabilities in the wave functions for the GLSSA13 model which resulted in unphysical solvation energy differences of up to −150 eV between different intermediates. For CANDLE on the other hand, constantly similar unphysical solvation energies of the order of 0.1 eV were obtained.
|
|