The Nobel Prize in Physiology and Medicine (1998) was awarded for the finding that nitric oxide (NO) is a ubiquitous signalling molecule in the cardiovascular system. Its biological function is related with vasodilation and thus is involved in therapies for chest pain and erectile dysfunction. Nitric oxide, along with nitrogen dioxide, plays a significant role in combustion chemistry and it is one of the most important pollutants in urban atmosphere. For example, nitric oxide destroys ozone in the upper atmosphere and, again unfortunately, creates ozone in the troposphere. The project aims to be the first joint systematic experimental and theoretical study of the microscopic structure and molecular motion of NO in the liquid and gas phase.