~~NOTOC~~
====== Dev's Corner ======
----
Here we give some hints on how to extend //potfit//. In particular, we list some common pitfalls that are to be avoided.

====  Indentation  ====

//potfit// source code is indented according to the default emacs indentation. The same effect can be achieved with the [[http://www.gnu.org/software/indent/|GNU indent command]], version >=2.2.10, using the following command:

<code bash>indent -gnu -cdw -cli4 -npsl -npcs -di6 -ncs -ce -br -brs -nlp -hnl -l110 -bbo 
 -T real -T apot_table_t -T pot_table_t -T vector -T sym_tens -T neigh_t -T atom_t -T FILE -T Param_T -T Interaction_T *.[[ch]]</code>

Sections that are NOT to be indented in this way have to be marked with

<code>/* *INDENT-OFF* */</code>

at their beginning and

<code>/* *INDENT-ON* */</code>

at their end, each control comment on a line of its own.

====  Introducing new parameters  ====

Before a new parameter can be used, it must be

  * declared and initialized to default value (in file ''potfit.h'')
  * read into potfit (routine getparamfile() in file ''param.c'')
  * possibly checked for nonsense values (routine ''check_parameters_complete()'' in file ''param.c'')
  * broadcast to the other CPUs (routine ''broadcast_params()'' in file ''mpi_utils.c'')

====  Naming conventions for files  ====

  * Source files are all named with lower case letters
  * Non-source files in the source directory begin with a capital letter (e.g. Makefile, README, INSTALL)
  * Documentation should be written, in English and in HTML or Wiki-Markup.