Sökning: "van der waals interactions"

Visar resultat 1 - 5 av 86 avhandlingar innehållade orden van der waals interactions.

1. 1. van der Waals Density Functionals

   Författare :Ylva Andersson; Chalmers tekniska högskola; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; van der Waals molecules; physisorption; van der Waals interactions; density-functional theory; exchange-correlation energy; scanning-force microscopy; adhesion;

   Sammanfattning : Methods using local or semi local approximations (LDA, GGA etc.) for the exchange-correlation energy in the density-functional theory (DFT) do not include van der Waals interactions. LÄS MER

3. 2. Van der Waals Interactions in Density Functional Theory

   Författare :Erika Hult; Chalmers tekniska högskola; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; van der Waals interaction; exchange-correlation energy; adhesion; intermolecular forces; physisorption; density functional theory;

   Sammanfattning : Density functional theory is a very important method for calculating ground-state properties for atoms, molecules and solids. Albeit exact in principle, its implementation requires an approximation for the so-called exchange-correlation energy. LÄS MER

4. 3. Van der Waals density-functional description of polymers and other sparse materials

   Författare :Jesper Kleis; Chalmers tekniska högskola; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; softmatter; Density functional theory; polyethylene; van der Waals interaction; polymer crystal; nanotubes; DFT; sparse material systems; polymer interactions; polymer structure;

   Sammanfattning : Polymers are abundant in nature --- rubber, tar and latex have been known to mankind for thousands of years. Early in the 20th century, a systematic synthesis of polymers was developed, but the great potential of synthesized polymers was recognized first during World War II. LÄS MER

5. 4. Van der Waals and Casimir interactions near metal films

   Författare :Mathias Boström; G. D. Mahan; Linköpings universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

   Sammanfattning : This thesis deals with van der Waals and Casimir forces near metal films. Thick, thin and strictly two-dimensional metal films will be investigated. For many applications one can model a double quantum-well structure with two strictly two-dimensional metallic sheets. LÄS MER

7. 5. First-principles calculations of polymer interactions

   Författare :Jesper Kleis; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; polymer structure; polyvinylchloride.; polypropylene; polyethylene; sparse material systems; Density functional theory; polymer interactions; van der Waals interaction; polymer crystal; soft matter; DFT;

   Sammanfattning : This thesis reports on studies of interactions in sparse matter by first-principles calculations, in particular polymeric systems. The focus is on the three unbranched simple polymers: polyethylene (PE), isotactic polypropylene (PP) and isotactic polyvinylchloride (PVC), which together represent an important class of materials that form complexes stabilized by weak but long-range dispersive interactions. LÄS MER