Email Notifications to Users

I am working on the following Use Case :

The employees get terminated on the basis of Employee End Date.Now I want the users to receive Email Notification as soon as the terminated date is set.

I have defined a Workflow the above case with the activity as Email Notification .But I am not sure what to add in therecipients field as the email should be sent to one particular user who is to be terminated.

Please help me out with this issue.

Thanks and Regards,

Shatadiya Saha