I can provide you with some information on the topic.
Albert Einstein's involvement in the development of atomic bombs is a complex and controversial matter. While Einstein did not directly work on the Manhattan Project, which led to the creation of the atomic bombs during World War II, he did play a role in drawing attention to the potential of nuclear energy through his groundbreaking work on relativity and his famous equation E=mc^2.
Einstein himself was a pacifist and expressed regret about his indirect involvement in the creation of atomic weapons. He signed a letter to President Franklin D. Roosevelt in 1939, warning about the potential military applications of nuclear fission and urging the United States to conduct research in this area. However, he later expressed remorse for having written the letter and voiced his concerns about the destructive power of nuclear weapons.
It is important to note that the decision to develop and use atomic bombs during World War II was made by governments and military authorities, and Einstein's contributions to science were not made with the intention of creating weapons of mass destruction. Nevertheless, some people have criticized Einstein for his indirect role and have debated the moral implications of his scientific contributions.
Ultimately, whether Einstein should have felt guilty or not is a subjective question, and opinions on this matter can vary.