File point

Til ere are three types of calcii lation s in HyperCh ein sin file point, geoin etry optimi/atioii or m iniin i/ation, an d in oleciilar tlyn am ics. 

Add the new type and its mass to the file pointed to by the AtotTi fypcMass cri try of the Registry or the cheni.itii file for the appropriate force field. 

I hese param eters are found m the file pointed to by the... 

Atom types are defined in the file chem.rul. The atom types for each of the force fields are listed in the files pointed to by the AtomTypeMass entries associated with the specific force fields in the Registry or the chem.ini file. They are usually named typ.txt or typ.dbf, depending on whether text or dBASE format is used. For the AMBER force field, all variations use the same type file, defined in the [Amber] section of the Registry or the chem.ini file. It is usually called ambertyp.txt, if a text format file is used, indicated by FileFormat=Text or ambertyp.dbf, if a dBASE III format file is used, indicated by FileFormat=dbf. 

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). 

The 1-4 van der Waals interactions cannot be scaled in CHARMM but in newer CHARMM parameter sets some atom types (usually united atoms) use different parameters for 1 interactions. These are specified for BlO-t in the file pointed to by the 6-12Atom 14VDW entry, usually called nbd.txt(dbf). If an atom type is absent in the 6-12Atom 14VDW file, the normal parameters are used. The format of the 6-12Atom 14VDW file is also specified by the 6-12AtomVDWFormat entry for the parameter set. 

Newer, published CHARMM parameter sets override some of the combination rule generated parameters for some atom type pairs. These parameters are found in the file pointed to by the 6-12PairVDW entry for the parameter set, usually called npr.txt(dbf). The values of Ay and By for these are computed using equations (22) and (23) on page 178 by setting the 6-12PairVDWFormat entry to RStarEpsilon. 

Hydraulic shock Visualize what happens at home when a faucet is open. A solid shaft of water is moving through the pipes from file point where it enters the house to the faucet. This could be 100 pounds of water moving at 10 feet per second, about seven miles per hour. 

If this series converges in (he region around file point a, it can be used to calculate the function f(x) to a precision determined by the number of terms retained. Assuming that the series exists, the coefficients oan be determined. Certainly, c0 f(a) and, by successive, term-by-term differentiation the subsequent coefficients are evaluated. Thus, as... 

Fig. 5. Equilibrium between dilute solution of lithium polystyrene and styrene at different temperatures. - AG,/RT = nJC, = - nMe. Solvents cyclohexane (open points) and benzene (filed points)...

FIGURE 4 An entry in a process table pointing to the I/O table for that press, which points in turn to all associated files the file control block for one file points to the device control block for the device on which the file resides. 

In Exhibit A file point was made that a calibration result from the middle of a curve should never be arbitrarily thrown away. The same is not necessarify true of calibration points that define the upper and lower extremes of the curve. Why ... 

Results from the DIPPR project (5) were selected for heat capadty of liquid. The covers applies to temperatures from below the boil point to tonpaatures above the filing point for most of the compounds. Data were correlated with a series expandon in temperature. Equation (1-6). Results are in favorable agreement with data. Errors are about 5% or less udng the mrrelation. 

Loop continuously till end of file is encountered while not (endfile(Reader)) loop -- Reading a line from the file pointed by READER readline(Reader, L) wait for 5 ns ... 

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