Each line in the configuration files consists of a identifying the option being specified, and a which is a parameter to be used for this option. Some keywords require several lines of data. The specification of the keywords is case insensitive so that any combination of upper and lower case letters will have the same meaning. Hence, DCDfile and dcdfile are equivalent. The capitalization in the values, however, may be important.
Some values indicate file names, in which capitalization is critical.
Other values such as on or off are case insensitive. You will need to write code and compile NAMD to make use of this feature. At this point only pure Tcl syntax is allowed. These required parameters specify the most basic properties of the simulation. In addition, it is highly recommended that pairlistdist be specified with a value at least one greater than cutoff .