PHOTOINDUCED BOND BREAKING IN THE S-8 RING - AN AB-INITIO MOLECULAR-DYNAMICS SIMULATION

The microscopic mechanism of the recently observed bond breaking in th e S-8 ring illuminated by a pulsed laser is investigated by means of a n ab initio molecular-dynamics simulation. It is found that a bond in the S-8 ring is easily broken immediately after an electron in the hig hest occupied molecular orbital is excited to the lowest unoccupied mo lecular orbital. From the time dependence of the eigenvalues and the w ave functions obtained by the simulation, it is established that the b ond breaks in order to stabilize the anti-bonding states occupied by t he excited electron.