Is it the job of a developer to suggest IT requirements?

Question

I am the only developer working on a web application which is nearing to its end. Now we are looking into making it Live in maybe a couple of months time.

This is a web application for a non IT company. Though they have their own internal IT team, they have asked me on what will be the hardware requirements for the live servers eg. RAM, 32 bit or 64 bit.

Shouldn't the internal IT team be doing this or since I am the only person working on the project is it my resposiblity to let them know of the any specific hardware requirements which may impact the performance of the project?

The reason I am asking this question is that, I have not done this before. All the times I used to be given a server and asked to deploy apps on it. I never used to worry about the server configuration, etc.