We investigate the effect of molecular geometry and conformational flexibility on electronic coupling and charge transfer interactions within propeller-shaped perylene diimide (PDI) tetramer arrays ...

The ALMA radio telescope array in the Atacama Desert temporarily halted operations after a rare snowfall blanketed the base camp last week.

The C.I.A. offered a different assessment on Wednesday, with Mr. Ratcliffe stating it had collected new material on the state of Iran’s nuclear program and the sites American bombers struck.