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For any PSCF simulation program, the parameter file is read first, followed by a command script. The name of the command file is specified when the program is invoked as an argument of the -c command line option. The command file controls the sequence of operations that will be performed after the program is initialized by processing information from the parameter file.

The command file contains a sequence of commands that are read and executed in the order in which they appear. Each command begins with an all upper case label. Some commands take one or more parameters, which must appear after the upper case label, separated by whitespace. The program stops execution and returns control to the operating system when it encounters the command string 'FINISH' on a line by itself.

Full descriptions of all of the commands recognized by all three PSCF programs are given here.

Example: Command file for 1D SCFT

The following is a minimal command file for using the pscf_1d program to perform an SCFT calculation:

READ_W          in/w.bf
ITERATE
WRITE_W         out/w.bf
WRITE_C         out/c.rf
FINISH

In this example, we assume that the input chemical potential field file (which we refer to as a w field file) is located in a subirectory of the working directory named in/, and that output files are written to a subdirector named out/. This command file instructs the program to:

READ_W: Read in a chemical potential fields (w-fields) from a file named in/w.rf
ITERATE: Iteratively solve the SCFT equation, using the iterator algorithm and parameters that are specified in the parameter file.
WRITE_W: Write the converged chemical potential fields (w-fields) to a file out/w.rf
WRITE_C: Write the corresponding monomer concentration fields (c-fields) to a file out/c.rf
FINISH: finish execution and halt the main program

The FINISH command is always the last command in a command file.

File names as command arguments : Many commands take the names of input or output files as arguments. File names are given as paths that, by default, are specified relative to the current working directory, i.e., the directory from which the program executable was invoked. File name paths may thus include names of subdirectories of this directory and path separator slash characters. This default may be modified by using the "-i" and/or "-o" command line options to add prefixes to paths to input and output files, respectively. The above example is designed for a case in which pscf_1d is invoked without using either of these command line options, and in which it is invoked from a directory containing subdirectories named "in" and "out" that are being used for input and output files, respectively.

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