Day by day, the energy demand is exceeding due to consumption increasing world population and fast-growing industrialization. As a result, biggest problems of 21st century are how it affects environment. The disquiet caused excessive reliance on fossil fuels as raw materials for production energy, such coal, oil, natural gas. Around 13 terawatts needed every day more than 6.5 billion people aro...

Ultrafast (sub-picosecond) internal conversion can occur between electronic states without energetically accessible conical intersections. For that, the molecule must remain in a region of at least weak nonadiabatic coupling, multiplying odds transition, each with small probability. This phenomenon is discussed simple analytical model correlating instantaneous probability to lifetime.