Table of Contents

Running Molpro

On Unix systems, Molpro is accessed using the molpro unix command. The syntax is

molpro options datafile

Molpro’s execution is controlled by user-prepared data; if datafile is not given on the command line, the data is read from standard input, and program results go to standard output. Otherwise, data is taken from datafile, and the output is written to a file whose name is generated from datafile by removing any trailing suffix, and appending .out. The name datafile must not contain parenthesis, brackets, or other special characters like exclamation marks (!), question marks (?), slashes (/), backslashes (\), blanks( ), equality signs($=$), commas (,), semicolons (;), asterisks (*), or any kind of quotes. If the output file already exists, then the old file is appended to the same name with suffix .out_1, and then deleted. This provides a mechanism for saving old output files from overwriting. Note that the above behaviour can be modified with the -o or -s options.

For example, a serial Molpro calculation is started using

molpro mymolecule.inp

and this creates an output mymolecule.out. For larger calculations, it may be necessary to specify how much dynamic (stack) memory molpro can allocate, using the -m option:

molpro -m100 mymolecule.inp

This allocates 100 MW (megawords) of stack memory. Further options are necessary for parallel excution, see section specifying parallel execution. For parallel excutions, it is very important to read and understand also sections GA Installation notes and memory specifications.

General Options

Most options are not required, since sensible system defaults are usually set. Options as detailed below may be given, in order of decreasing priority, on the command line, in the environment variable MOLPRO_OPTIONS, or in the files ./molpro.rc, $HOME/.molprorc, and tuning.rc in the library files directory.

Options for launching Molpro

These options are for the molpro shell script which is used to launch the molpro.exe MPI program. These options should be given on the command line or in the MOLPRO_OPTIONS environment variable as both of these are parsed by the shell script and used to launch molpro.exe, they should not be given in .molprorc or any other configuration files since these are not read until after molpro.exe is launched.

Options for parallel execution

The options specific to parallel execution are described here.

It is very important to read running Molpro on parallel computers before executing parallel Molpro calculations.

Tuning Options

There are a number of other options for tuning and system parameters, but these do not usually concern the general user.

Tuning parameters for blas routines (mxma,, mxmb, mxva, mxvb):

Tuning parameters for fortran versions of mxma/mxmb:

It is not usually necessary to specify any of these options as there are sensible defaults. Sometimes installation dependent options can be found in the system configuration file molpro.rc in the same directory as the Molpro library files.