Ab initio study for Si-H bond vibration on the surface of silicon vacancy

Si-H bond vibrational frequency on the surface of silicon multivacancies an d platelets is estimated by the ab initio molecular dynamics method. There are two forms of hydrogen molecules considered whose vibrational frequencie s agree with the experimental ones, one is in silicon multivacancies and th e other is in silicon platelets which are planar vacancies. In this work, w e identify that the experimental peak frequency is due to hydrogen molecule s in platelets, from the information of Si-II bond vibrational frequency, p articularly its difference in broadness that is also observed in the experi ment.