MOLPRO

1 HOW TO READ THIS MANUAL 1
1 HOW TO READ THIS MANUAL
This manual is organized as follows: The next chapter gives an overview of the general structure
of MOLPRO. It is essential for the new user to read this chapter, in order to understand the
conventions used to define the symmetry, records and files, orbital spaces and so on. The later
chapters, which describe the input of the individual program modules in detail, assume that you
are familiar with these concepts. The appendices describe details of running the program, and
the installation procedure.
Throughout this manual, words in Typewriter Font denote keywords recognized by MOL-
PRO. In the input, these have to be typed as shown, but may be in upper or lower case. Numbers
or options which must be supplied by the user are in italic. In some cases, various different
forms of an input record are possible. This is indicated as [options], and the possible options are
described individually in subsequent subsections.
2 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. 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.
2.1 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.
-d dir1:dir2:... where dir1:dir2:... is a list of directories which may be used for
creating scratch files. Each of the directories should be writable
by those who will use the program, and the directory specification
may contain embedded environment variables in shell form, for
example $TMPDIR or /tmp/$USER; these will be expanded at
run time. If multiple scratch file systems are available, it is advantageous
to present a list of directories of which there is one in
each file system. Some parts of MOLPRO present extreme I/O demands,
and it is therefore important to be careful in optimizing the
provision and specification of scratch directories.
Note that in the building of bin/molpro, the environment variables
$TMPDIR, $TMPDIR2, $TMPDIR3,... are used to construct
the list of scratch directories for the -d option. Thus, these
environment variables should at make time be filled with the names