I havent spoken to my ex girlfriend in a month, should I call her?

Last month i broke up with my ex. We had a really bad relationship. I yelled and insulted her all the time because she hurt me all the time. She was immature, unconscious of her actions, and never spent time with me. I broke up because it broke my heart knowing she planned a summer program to go to when she never planned a day to be with me, and it made her happier than talking to me. We havent spoken to each other im a month. I really miss her, and i was thinking of calling her to talk and hang out for closure. I was hoping we can try again in the future, is this a good or bad idea? Should I just leave her alone or should i talk to her?