The invention is a method and device providing very high density information storage on an organometallic charge transfer data storage medium. The medium is switched from one state to another through the application of an electric field to the medium by the probe tip of a scanning tunneling microscope resulting in an observable change in the electron density of the surface of the medium. A STM tip is used to write, read and erase data via the organometallic charge transfer medium (e.g. TCNQ, or derivatives thereof).