期刊名称:Proceedings of the National Academy of Sciences
印刷版ISSN:0027-8424
电子版ISSN:1091-6490
出版年度:2018
卷号:115
期号:44
页码:E10295-E10302
DOI:10.1073/pnas.1811569115
语种:English
出版社:The National Academy of Sciences of the United States of America
摘要:General properties of the recently observed screening of the van der Waals (vdW) attraction between a silica substrate and silica tip by insertion of graphene are predicted using basic theory and first-principles calculations. Results are then focused on possible practical applications, as well as an understanding of the nature of vdW attraction, considering recent discoveries showing it competing against covalent and ionic bonding. The traditional view of the vdW attraction as arising from pairwise-additive London dispersion forces is considered using Grimme’s “D3” method, comparing results to those from Tkatchenko’s more general many-body dispersion (MBD) approach, all interpreted in terms of Dobson’s general dispersion framework. Encompassing the experimental results, MBD screening of the vdW force between two silica bilayers is shown to scale up to medium separations as 1.25 d e/ d , where d is the bilayer separation and d e is its equilibrium value, depicting antiscreening approaching and inside d e. Means of unifying this correlation effect with those included in modern density functionals are urgently required.
关键词:van der Waals screening ; Faraday cage ; covalent bonding ; many-body dispersion ; Dobson B