Standalone molecular mechanics program. This program reads a Gaussian input file from standard input and writes a new input file with the (possibly optimized) structure to standard output. The desired force field must be selected via the -Dreiding, -UFF, -Amber or -Param option (see below for the latter). The type of job to run is specified with the -Force, -Freq, -Opt, and -Micro command line options; the default is an energy calculation. -Micro optimizes only the atoms that are in the low ONIOM layer (i.e., the real system), in order to preoptimize the MM portion of the molecule.
-Param N
Use force field N (same as IOp(1/64)=N within Gaussian).
-ReadParam
Read in additional parameters. Internally-stored parameters have priority over read-in parameters.
-ReplaceParam
Read in additional parameters. Read-in parameters take priority over the internally-stored parameters.
-OptCyc N
Specify the maximum number of optimization cycles to N.
-ReadCon
Read connectivity information from the input file (i.e., the input file uses Geom=Connect).
-Test N
Set the debugging flag to N (higher numbers result in more debugging output).
-TRScale num
Use scaling scheme num for rigid translations/rotation: 0=no scaling (the default); 1 says to scale the N atoms in a rigid block by 1/N; 2 says to scale the N atoms in a rigid block by 1/SQRT(N), and a negative value scales by |N|/1000.
-External
Read input and write output in the formats used by the External keyword.
Last update: 23 April 2013