Running a Program (Prev) Parameter Files (Next)

The PSCF package allows users to perform two primary types of field theoretic calculation of material properties. These are:

Self-Consistent Field Theory (SCFT)
Field Theoretic Simulation (FTS)

All three PSCF programs (pscf_1d, pscf_pc and pscf_pg) can perform SCFT calculations. Field theoretic simulations that rely on either Monte-Carlo or Brownian dynamics sampling can be performed with the pscf_pc and pscf_pg programs for periodic systems, but not with the pscf_1d program.

All three PSCF programs can also perform SCFT parameter sweeps. A parameter sweep is an operations that performs a sequence of SCFT calculations for slightly different choices of parameter values spaced along a path through parameter space, as discussed in more detail here.

Each of the PSCF programs is initialized using data in a parameter file and then executes a series of commands specified in a command file. The following commands performs one of the types of calculation described above:

ITERATE performs a single SCFT calculation
SWEEP performs an SCFT parameter sweep
SIMULATE performs an FTS calculation

The format of a parameter file contains some optional elements that are required for some types of calculations but unnecessary for others. The required format of a parameter file depends to some extent on what type of commands are used in the associated command file.

For example, consider a parameter file that is designed to be initialize an SCFT calculation, by using it together with a command file that invokes the ITERATE or SWEEP command. The parameter file for such a calculation must information that specifies a specifies a choice of SCFT iteration algorithm from among several possible algorithms, and that specifies values of parameters required by that algorithm. This information is given in a section of the parameter file that is referred to in what follows as an Iterator block. The Iterator block is an optional component of a PSCF parameter file that is needed for SCFT calculations but is not used in a FTS. Conversely, a parameter file used to initialize a FTS calculation must contain other specialized blocks that specify information MC or BD sampling algorithms, none of which is necessary for SCFT.

The discussion of parameter files that begins on the following page focuses on examples that describe elements needed for SCFT calculations and SCFT parameter sweeps. Parameter file sections that are needed only for FTSs are discussed separately.

Running a Program (Prev) User Introduction (Up) Parameter Files (Next)