This paper outlines the beginnings of a general theory of critical events. Four types are defined. Two are micro-events each affecting a small number of people and are shown to arise in everyday life. Two are macro-events that affect large numbers of people and are related to ‘shocks’ in...

A new perovskite like system [NH3-(CH2)10-NH3] ZnCl4, has been synthesized and characterized by single crystal X-ray diffraction, thermal analysis and infrared spectroscopic study. This compound crystallize in a triclinic space group P-1, with the unit cell parameters a=7.294(1), b=10.058(9) Å,...