Registry parameter

The form that single atom type constants take is selected by setting the Registry/chem.ini parameter set entry 6-12AtomVDWFormat to one of RStarEpsilon, SigmaEpsilon or SlaterKirkwood. This specifies the combination rules that are used for the file pointed to by the 6-12AtomVDW entry in the Registry or the chem.ini file for the same parameter set. 

The functional form for bond stretching in AMBER is quadratic only and is identical to that shown in equation (11) on page 175. The bond stretching force constants are in units of kcal/mol per A and are in the file pointed to by the QuadraticStretch entry for the parameter set in the Registry or the chem.ini file, usually called =>istr.txt(dbf). 

The functional form for van der Waals interactions in AMBER is identical with that shown in equation (13) on page 175. The coefficients A. and B.. are computed from the parameters in the file pointed to by the 6-12AtomVDW entry for the parameter set in the Registry or the chem. ini file, usually called nbd.txt(dbf), and optionally with the file pointed to by the 6-12PairVDW entry for the parameter set, usually called npr.txt(dbf). The standard AMBER parameter sets use equations (15) and (16) for the combination rules by setting the 6-12AtomVDWFormat entry to RStarEpsilon. The 1 van der Waals interactions are usually scaled in AMBER to half their nominal value (a scale factor of 0.5 in the Force Field Options dialog box). 

To obtain a reliable value of from the isotherm it is necessary that the monolayer shall be virtually complete before the build-up of higher layers commences this requirement is met if the BET parameter c is not too low, and will be reflected in a sharp knee of the isotherm and a well defined Point B. For conversion of into A, the ideal adsorptive would be one which is composed of spherically symmetrical molecules and always forms a non-localized film, and therefore gives the same value of on all adsorbents. Non-localization demands a low value of c as c increases the adsorbate molecules move more and more closely into registry with the lattice of the adsorbent, so that becomes increasingly dependent on the lattice dimensions of the adsorbent, and decreasingly dependent on the molecular size of the adsorbate. 

Polymer CAS Registry Number L Density at 20°C,K/cm" SolubiHty parameter Refractive index,... 

Compound CAS Registry Number Boiling point, °C Density at 20°C, g/cm Dipole moment, 10-"° Cm Index of refraction, < PR nmr Parameters chemical t shift, ppm ... 

Solvent name CAS Registry Number Common name (trade name) Empirical formula I[Pg.264]

Film CAS Registry Number Growth parameter cmVC L, nm... 

In the conesponding model of an interface, when tire lattice parameters of the two phases in contact are different, there will be a dis-registry at the interface defined by... 

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