Question: What country is the person who discovered the quantum mechanical model of the atom a citizen of?

full_context: Document 1: Bohr–Einstein debates: The quantum revolution of the mid-1920s occurred under the direction of both Einstein and Bohr, and their post-revolutionary debates were about making sense of the change. The shocks for Einstein began in 1925 when Werner Heisenberg introduced matrix equations that removed the Newtonian elements of space and time from any underlying reality. The next shock came in 1926 when Max Born proposed that mechanics were to be understood as a probability without any causal explanation.
Document 2: Planck constant: Niels Bohr introduced the first quantized model of the atom in 1913, in an attempt to overcome a major shortcoming of Rutherford's classical model. In classical electrodynamics, a charge moving in a circle should radiate electromagnetic radiation. If that charge were to be an electron orbiting a nucleus, the radiation would cause it to lose energy and spiral down into the nucleus. Bohr solved this paradox with explicit reference to Planck's work: an electron in a Bohr atom could only have certain defined energies En
Document 3: Niels Bohr: Bohr founded the Institute of Theoretical Physics at the University of Copenhagen, now known as the Niels Bohr Institute, which opened in 1920. Bohr mentored and collaborated with physicists including Hans Kramers, Oskar Klein, George de Hevesy, and Werner Heisenberg. He predicted the existence of a new zirconium-like element, which was named hafnium, after the Latin name for Copenhagen, where it was discovered. Later, the element bohrium was named after him.
Document 4: Warsaw Pact: On 23 October 1954 – only nine years after Allies (UK, USA and USSR) defeated Nazi Germany ending World War II in Europe – the admission of the Federal Republic of Germany to the North Atlantic Pact was finally decided. The incorporation of West Germany into the organization on 9 May 1955 was described as "a decisive turning point in the history of our continent" by Halvard Lange, Foreign Affairs Minister of Norway at the time. In November 1954, the USSR requested a new European Security Treaty, in order to make a final attempt to not have a remilitarized West Germany potentially opposed to the Soviet Union, with no success.
Document 5: Schrödinger's cat: Schrödinger's cat is a thought experiment, sometimes described as a paradox, devised by Austrian physicist Erwin Schrödinger in 1935. It illustrates what he saw as the problem of the Copenhagen interpretation of quantum mechanics applied to everyday objects. The scenario presents a hypothetical cat that may be simultaneously both alive and dead, a state known as a quantum superposition, as a result of being linked to a random subatomic event that may or may not occur.
Document 6: John von Neumann: The physics of quantum mechanics was thereby reduced to the mathematics of Hilbert spaces and linear operators acting on them. For example, the uncertainty principle, according to which the determination of the position of a particle prevents the determination of its momentum and vice versa, is translated into the non-commutativity of the two corresponding operators. This new mathematical formulation included as special cases the formulations of both Heisenberg and Schrödinger. When Heisenberg was informed von Neumann had clarified the difference between an unbounded operator that was a Self-adjoint operator and one that was merely symmetric, Heisenberg replied "Eh? What is the difference?"
Document 7: Vacuum: In 1930, Paul Dirac proposed a model of the vacuum as an infinite sea of particles possessing negative energy, called the Dirac sea. This theory helped refine the predictions of his earlier formulated Dirac equation, and successfully predicted the existence of the positron, confirmed two years later. Werner Heisenberg's uncertainty principle formulated in 1927, predict a fundamental limit within which instantaneous position and momentum, or energy and time can be measured. This has far reaching consequences on the "emptiness" of space between particles. In the late 20th century, so-called virtual particles that arise spontaneously from empty space were confirmed.
Document 8: Pakistan and weapons of mass destruction: At the Multan meeting, Bhutto also appointed Munir Ahmad Khan as chairman of PAEC, who, until then, had been working as director at the nuclear power and Reactor Division of the International Atomic Energy Agency (IAEA), in Vienna, Austria. In December 1972, Abdus Salam led the establishment of Theoretical Physics Group (TPG) as he called scientists working at ICTP to report to Munir Ahmad Khan. This marked the beginning of Pakistan's pursuit of nuclear deterrence capability. Following India's surprise nuclear test, codenamed Smiling Buddha in 1974, the first confirmed nuclear test by a nation outside the permanent five members of the United Nations Security Council, the goal to develop nuclear weapons received considerable impetus.
Document 9: West Germany: The foundation for the influential position held by Germany today was laid during the Wirtschaftswunder (economic miracle) of the 1950s when West Germany rose from the enormous destruction wrought by World War II to become the world's third - largest economy. The first chancellor Konrad Adenauer, who remained in office until 1963, had worked for a full alignment with NATO rather than neutrality. He not only secured a membership in NATO but was also a proponent of agreements that developed into the present - day European Union. When the G6 was established in 1975, there was no question whether the Federal Republic of Germany would be a member as well.
Document 10: History of science: In 1938 Otto Hahn and Fritz Strassmann discovered nuclear fission with radiochemical methods, and in 1939 Lise Meitner and Otto Robert Frisch wrote the first theoretical interpretation of the fission process, which was later improved by Niels Bohr and John A. Wheeler. Further developments took place during World War II, which led to the practical application of radar and the development and use of the atomic bomb. Though the process had begun with the invention of the cyclotron by Ernest O. Lawrence in the 1930s, physics in the postwar period entered into a phase of what historians have called "Big Science", requiring massive machines, budgets, and laboratories in order to test their theories and move into new frontiers. The primary patron of physics became state governments, who recognized that the support of "basic" research could often lead to technologies useful to both military and industrial applications. Currently, general relativity and quantum mechanics are inconsistent with each other, and efforts are underway to unify the two.
Document 11: Max Planck Society: The Max Planck Society and its predecessor Kaiser Wilhelm Society hosted several renowned scientists in their fields, including luminaries such as Otto Hahn, Werner Heisenberg, and Albert Einstein.
Document 12: Bohr model: In 1925, a new kind of mechanics was proposed, quantum mechanics, in which Bohr's model of electrons traveling in quantized orbits was extended into a more accurate model of electron motion. The new theory was proposed by Werner Heisenberg. Another form of the same theory, wave mechanics, was discovered by the Austrian physicist Erwin Schrödinger independently, and by different reasoning. Schrödinger employed de Broglie's matter waves, but sought wave solutions of a three - dimensional wave equation describing electrons that were constrained to move about the nucleus of a hydrogen - like atom, by being trapped by the potential of the positive nuclear charge.
Document 13: John von Neumann: Von Neumann was the first to establish a rigorous mathematical framework for quantum mechanics, known as the Dirac–von Neumann axioms, with his 1932 work Mathematical Foundations of Quantum Mechanics. After having completed the axiomatization of set theory, he began to confront the axiomatization of quantum mechanics. He realized, in 1926, that a state of a quantum system could be represented by a point in a (complex) Hilbert space that, in general, could be infinite-dimensional even for a single particle. In this formalism of quantum mechanics, observable quantities such as position or momentum are represented as linear operators acting on the Hilbert space associated with the quantum system.
Document 14: University of Chicago: Notable faculty in physics have included the speed of light calculator A. A. Michelson, elementary charge calculator Robert A. Millikan, discoverer of the Compton Effect Arthur H. Compton, the creator of the first nuclear reactor Enrico Fermi, "the father of the hydrogen bomb" Edward Teller, "one of the most brilliant and productive experimental physicists of the twentieth century" Luis Walter Alvarez, Murray Gell-Mann who introduced the quark, second female Nobel laureate Maria Goeppert-Mayer, the youngest American winner of the Nobel Prize Tsung-Dao Lee, and astrophysicist Subrahmanyan Chandrasekhar.
Document 15: Göttingen Manifesto: The Göttingen Manifesto was a declaration of 18 leading nuclear scientists of West Germany (among them the Nobel laureates Otto Hahn, Max Born, Werner Heisenberg and Max von Laue) against arming the West German army with tactical nuclear weapons in the 1950s, the early part of the Cold War, as the West German government under chancellor Adenauer had suggested.
ground_truth: West Germany
sub_queries: who discovered the quantum mechanical model of the atom Answer: Werner Heisenberg
Werner Heisenberg >> country of citizenship Answer: West Germany