I understand that it is usually not difficult for PI to find another professor in the same campus or city for collaboration on a multi-field project (e.g. computational chemistry). However, when the demand of long term collaboration is not huge, would PIs consider to hire some outsiders or consulting companies to do the work? And is it allowed under NIH funding systems?
(For example, a task may only require a few hundreds line of coding, which can be done by an experienced programmer in the field. The work may be a bit too lack of rewards for a new collaborator. Wouldn't it be cheaper and more realistic for a chemistry PI to hire a consultant in this case, than getting a new PhD student or post-doc in programming? )