While in the middle of a divorce my wife moves moves into a new home abandoned me what legal grounds do I have

Grounds for what?  If you are "in the middle of a divorce" then separation was presumably inevitable, and the fact of either of you doing so during the case does not provide "grounds" for anything except perhaps an adjustment of what money, if any, is paid to or from one of you to the other, unless there are children involved, in which case the separation gives rise to a need for an agreement or order as to their custody, visitation, and support.  There is not enough information to go on here; if you have questions, you should consult with a family law specialist.