 Then, Riazuddin, with the help of his mentor, Dr. Abdus Salam, convinced the then PAEC chairman Dr. Ishrat Hussain Usmani to send all the theoreticians to the Institute of Physics to form a physics group.This established the "Theoretical Physics Group" (TPG), which later designed nuclear weapons for Pakistan.With the establishment of TPG, Siddiqui began to work with Abdus Salam, and on his advice began research in Theoretical Physics at PAEC.