SCRIPT

This new quantity Sv p, the negative of which De Bonder (1920) has called the affinity and given the symbol of a script A, is obviously the important thennodynamic fiinction for chemical equilibrium ... 

One significant characteristic of the program is the Command Line. Hereby, the visualization of the molecules is directed in the viewer with commands from a script language. The scripts, such as loop or batch files, can be saved, lutp //openrasmoi.org... 

The predictions are sent back to the client web browser and visualized using a combination of HTML, JavaScript [50], MDL Chime [51] scripting, and Java applets. 

You can obtain detailed results of ealeulation s by using Start I ig on th e File ni en u. The amount of calcu lational results is con trolled by the Qnan tn111PrintLcvel. The QnantuinPriiitLcvel can be changed In the CTIEM.IXI file before you run IlyperCheni or by a script command after you are running IlyperChem. For more detailsofthe log file and information saved in the log file, see the IlyperC hem Reference in an ual. 

Coordin ates of atom s can he set by n orm al translation orrotation of HyperCh cm molecules, fo set initial velocities, however, it is necessary to edit th e H l. file explicitly. The tin it o f velocity in the HIN file is. An gstrom s/picosecon d.. Areact.hin file and a script react.scr are in eluded with HyperChem to illustrate one simple reacting trajectory. In order to have these initial velocities used in a trajectory the Restart check box of the Molecular Dynamics Option s dialog box must he checked. If it is n ot, the in itial velocities in the HIN file will be ignored and a re-equilibration to the tern peratiire f of th e Molecular Dyn am ics Option s dialog box will occur. This destroys any imposed initial conditions on the molecular dynamics trajectory. 

Note the use of a script for the binary pair mutual diffusion coefficient, as distinct from the Roman D already used to represent Knudsen diffusion coefficients. This convention will be adhered to throughout. 

The calculated result as we have found it by this dissection of the G2 method agrees with the final result of the G2 script... 

The program comes with its own job queue system. Jobs are submitted to this queue via a script, which can be edited to utilize third-party batch-queuing systems instead. 

The calculation setup screens list a good selection of the options that are most widely used. However, it is not a complete list. The user also chooses which queue to use on the remote machine and can set queue resource limits. All of this is turned into a script with queue commands and the job input file. The user can edit this script manually before it is run. Once the job is submitted, the inputs are transferred to the server machine, the job is run and the results can be sent back to the local machine. The server can be configured to work with an NQS queue system. The system administrator and users have a reasonable amount of control in configuring how the jobs are run and where files are stored. The administrator should look carefully at this configuration and must consider where results will be sent in the case of a failed job or network outage. 

Crystal (we tested Crystal 98 1.0) is a program for ah initio molecular and band-structure calculations. Band-structure calculations can be done for systems that are periodic in one, two, or three dimensions. A separate script, called LoptCG, is available to perform optimizations of geometry or basis sets. 

The ASCII input file includes elements of a scripting language. Thus, the input can contain variables, loops, and procedures. This is one of the aspects of the program that makes it possible to do very complex calculations. The documentation describes the input options, but does not discuss when and why they should be used. The user must have a solid understanding of ah initio theory in order to correctly utilize many of the functions in this program. It is very powerful, but not for beginners. 

There is a screen to set up the calculation that has menus for the most widely used functions. Many users will still need to know many of the keywords, which can be typed in. There was no default comment statement, so the input file created would not be valid if the user forgot to include a comment. A calculation can be started from the graphic interface, which will be run interactively by default. The script that launches the calculation was not too dilficult to modify for use with a job-queueing system. 

Organic chemists have devised a number of shortcuts to speed the writing of structural formulas Sometimes we leave out unshared electron pairs but only when we are sure enough m our ability to count electrons to know when they are present and when they re not We ve already mentioned representing covalent bonds by dashes In condensed structural formulas we leave out some many or all of the covalent bonds and use sub scripts to indicate the number of identical groups attached to a particular atom These successive levels of simplification are illustrated as shown for isopropyl alcohol ( rub bmg alcohol )... 

Figure 15.22 Phase 1 (noble) dark script. Phase II light background. (Magnification 500x, etched nitric acid.)...

Script files A seript file is an ASCII text file of MATLAB eommands, that ean be ereated using... 

The script file exampSSa.m shows how this is achieved... 

Case study Example 5.11 uses root locus to design a ship roll stabilization system. The script file exampSll.m considers a combined PD and PID (PIDD) controller of the form... 

This script file produces the root locus shown in Figure 5.24 and allows the user to select the value of K furthest from the imaginary axis that corresponds to ( = 0.7. The command window text is... 

The script file examp61h.m shows how it is possible to customize a Bode diagram... 

Note that to obtain a reasonable diagram, it is usually necessary for the user to define the scales of the x and y axes using the axis command. The script file examp64a.m produces the Bode gain diagrams for the same system when K = A and 8, see Figure 6.23(a). 

Script file fig627.m produces the Nichols chart for Example 6.4 when K = 4, as illustrated in Figure 6.27. The command ngrid produces the closed-loop magnitude and phase contours and axis provides user-defined axes. Some versions of MATLAB appear to have problems with the nichols command. 

Running script file fig629.m will produce the closed-loop frequency response gain diagrams shown in Figure 6.29 for Example 6.4 when K = 3.8 and 3.2 (value of K for best flatband response). 

Script file examp77.m plots the closed-loop step responses of both the continuous system and discrete system (see Figure 7.21). In the latter case the plant pulse transfer function uses zoh, and the compensator is converted into discrete form using... 

The continuous and discrete closed-loop systems are shown in Figures 7.22(a) and (b). The digital compensator is given in equation (7.128). Script file examp78.m produces the step response of both systems (Figure 7.25) and prints the open and closed-loop continuous and pulse transfer functions in the command window... 

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