VASP

We shall first review the basic principles of VASP and than describe exemplary applications to alloys and compounds (a) the calculation of the elastic and dynamic properties of a metallic compound (CoSi2), (b) the surface reconstruction of a semiconducting compound (SiC), and (c) the calculation of the structural and electronic properties of K Sbi-j, Zintl-phases in the licpiid state. 

Given the efficiency of VASP, electronic structure calculations with or without a static optimization of the atomic structure can now be performed on fast workstations for systems with a few hundred inequivalent atoms per cell (including transition-metais and first row elements). Molecular dynamics simulationsextending over several picoseconds are feasible (at tolerable computational effort) for systems with 1000 or more valence electrons. As an example we refer to the recent work on the metal/nonmetal transition in expanded fluid mercury[31]. 

In the following we review very briefly applications of VASP to alloys and inter-metallic compounds illustrating the potential in making ab-initio predictions of materials properties, in characterizing solid surfaces, and in studying the structure and properties of complex melts. For a more extensive list of applications, see Refs. [10, 17]. 

Table 2 Lattice parameter ao (in A) and elastic constants B, Cn, C12, and C44 for CoSi2 (in GPa), calculated using all-electron (FLAPW) and pseudopotential (VASP) techniques in the LDA and using GGC corrections.

The performance of VASP for alloys and compounds has been illustrated at three examples The calculation of the properties of cobalt dislicide demonstrates that even for a transition-metal compound perfect agreement with all-electron calculations may be achieved at much lower computational effort, and that elastic and dynamic properties may be predicted accurately even for metallic systems with rather long-range interactions. Applications to surface-problems have been described at the example of the. 3C-SiC(100) surface. Surface physics and catalysis will be a. particularly important field for the application of VASP, recent work extends to processes as complex as the adsorption of thiopene molecules on the surface of transition-metal sulfides[55]. Finally, the efficiciency of VASP for studying complex melts has been illustrate for crystalline and molten Zintl-phases of alkali-group V alloys. 

Calculations were performed within the periodic DFT model, using the VASP code[8] (the same computational strategy as in Ref. [9] was adopted, including the B3LYP correction). Thus, calculated interaction energies are of the B3LYP quality and they include ZPVE correction. The unit cell of FER fitted previously was used [10] UC... 

Kato, A., Ozawa, F., Saitoh, Y., Hirai, K., and Inokuchi, K. (1997) vesl, a gene encoding VASP/Ena family related protein, is upregulated during seizure, long-term potentiation and synaptogenesis. FEBS Lett. 412,183-189. 

VASP, vasodilator stimulated phosphoprotein hsp27, heat shock protein hsp27 LASP, LIM and SH3 domain containing protein Tx, thromboxane IP3, inositol triphosphate ADP, adenosine 5 -diphosphate. Adapted from Refs. [44] and [116]. 

VASP Inhibits VASP binding to F-actin inhibits VASP localization to focal contacts and integrins... 

SIN-1 spontaneously releases NO and superoxide under physiological conditions thereby stimulating cGMP production. SIN-1 significantly decreased expression of P-selectin and both total and activated GP Ilb/IIIa and also promoted reversal of activated GP Ilb/IIIa complex in platelets stimulated with thrombin [61]. However, in rats SIN-1 could only partially reduce the degree of platelet activation [62]. SIN-1 stimulated VASP Ser157 phosphorylation and inhibited GP Ilb/IIIa activation. Threshold... 

Calculations in Roudgar et al. focused on the shortest SGs (i.e., CF3SO3H) under conditions of minimal hydration (i.e., with one H2O per SG). The main parameter considered is the nearest neighbor distance of the terminal, fixed C atoms. It was varied from 5 A < dec 12 A, which encompasses the range of side chain separations found in prototypical ionomer membranes. The VASP based on DFT was used. Figure 6.13 displays the formation... 

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