If the employee has any University property in their possession, state that it must be returned. Also, instruct the employee to contact you to establish a meeting time to have the University property returned and to allow the employee to pick up their personal property.
"Any University property in your possession must be returned to me. Contact me at [phone number] to schedule a mutually convenient meeting time for the return of University property. At this meeting, you may also pick up any personal property that you may have left here. I expect to hear from you by [date]."