Q-Chem 4.3 User’s Manual

3.7 $rem Array Format in Q-Chem Input

All data between the $rem keyword and the next appearance of $end is assumed to be user $rem array input. On a single line for each $rem variable, the user declares the $rem variable, followed by a blank space (tab stop inclusive) and then the $rem variable option. It is recommended that a comment be placed following a space after the $rem variable option. $rem variables are case insensitive and a full listing is supplied in Appendix C. Depending on the particular $rem variable, $rem options are entered either as a case-insensitive keyword, an integer value or logical identifier (true/false). The format for describing each $rem variable in this manual is as follows:


A short description of what the variable controls.


The type of variable, i.e. either INTEGER, LOGICAL or STRING


The default value, if any.


A list of the options available to the user.


A quick recommendation, where appropriate.

Example 3.14  General format of the $rem section of the text input file.

  REM_VARIABLE  value  [ user_comment ]
  REM_VARIABLE  value  [ user_comment ]

Note: (1) Erroneous lines will terminate the calculation.
(2) Tab stops can be used to format input.
(3) A line prefixed with an exclamation mark ‘!’ is treated as a comment and will be ignored by the program.