# 11 Input files

The input file of the Mrcc package is the MINP file. This file must be placed in the directory where the program is invoked. In addition, if you use your own basis sets (see keyword basis), angular integration grids for DFT calculations (see keyword agrid), or Laplace-quadrature for Laplace transform calculations (see keyword dendec), you may also need the GENBAS file, and then it must be also copied to the above directory.

In general, the execution of Mrcc is controlled by keywords. The list of the keywords is presented in Sect. 12. The keywords and the corresponding options must be given in the MINP file as

$<$keyword$>$[=$<$option$>$]

You can add only one keyword per line, but there are keywords which require multiple-line input, and the corresponding variables must be specified in the subsequent lines as

$<$keyword$>$[=$<$option$>$]
$<$input record 1$>$
$<$input record 2$>$

$<$input record n$>$

The input is not case-sensitive. Any number of lines can be left blank between two items, however, if a keyword requires multiple-line input, the lines including the keyword and its input records cannot be separated. Under similar conditions any line can be used for comments, but the beginning of a comment line must not be identical to a keyword because that line may be identified as a keyword by the input reader and misinterpreted. Thus it is recommended to start comment lines with some special character, e.g., hash mark.

Please note that you can find input files for numerous test jobs in the MTEST directory created at the installation of Mrcc (see Sect. 8). The input files have self-explanatory names and also include a short description at the beginning. You should look at these files for examples for the structure of the input file and the use of various keywords. You can use these files as templates, but please note that these files have been created to thoroughly check the correctness of the code and the installation, and thus some of them contain very tight convergence thresholds as well as unusual combination of (auxiliary) basis sets. In production calculations, you should use the default convergence thresholds (i.e., delete the lines including keywords itol, scftol, cctol, etc.), select the basis set carefully (i.e., set the appropriate option for keyword basis), and use the default auxiliary basis sets (i.e., delete the lines including keywords dfbasis_scf or dfbasis_cor). Please also do not forget to remove keyword test and to specify the amount of memory available to the program by setting the mem keyword.