Customizing VMD Sessions

There are a number of ways to change the behavior of VMD from the default settings, both in how the program starts up and in how the program behaves during a session. This Chapter describes the data files, command-line options, and environment variables which are used to customize a VMD session.

These files control the initial appearance and behavior of VMD at the start, and may be customized to suit each user's particular tastes. Default versions of these files are placed in the VMD installation directory (On Unix this is usually /usr/local/lib/vmd, on Windows this defaults to C:\Program Files\University of Illinois\VMD ). Each user may specify their own versions of some of these files, but unless this is done the commands and values in the default files are used. In this way, an administrator may customize the default behavior of VMD for all users, while giving each user the option to change the default behavior however they choose.

Several configurable parameters may also be set in a number of ways, including use of command-line options or environment variables. The order of precedence of these methods is as follows (highest precedence to lowest):

1. Command-line options.
2. Environment variable settings.
3. Built-in defaults, as specified by compilation configurable parameters. These are used only if no other values are specified by the other methods mentioned in this list. The Installation Guide describes how to change these default values when compiling VMD.