 In 1970, he established the Mathematical Physics Group (MPG) at PAEC, where he led academic research in advanced mathematics.He also delegated mathematicians to PAEC to specialise in their fields at the MPG Division of PAEC.After the Indo-Pakistani War of 1971, Siddiqui joined the Pakistan Atomic Energy Commission (PAEC) at the request of Prime Minister Zulfikar Ali Bhutto.