====== 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 Molpro. 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.