Update 19 June 2013:
A much better written and complete guide to getting started with MD in ECCE+NWChem is found here: http://saccharides.blogspot.tw/2013/06/ecce-md-calculation.html
Here's a multi-part description of how to set up a minimal MD simulation using ECCE/NWChem. To make things real easy we'll do an example with a fully described and parametrised system.
How to install and configure ecce is described elsewhere on this blog.
Start Ecce, select Organizer
Back in the organiser set the size of the box for the system
If all goes well you'll be able to launch your job, which will finish very fast.
Part 2 will do the next step -- MD Optimize