The theoretical cluster-Bethe-lattice method is used to calculate the electronic and vibrational densities of states of the local bonding structures containing SiH, SiH2, NH and NH2 groups The Si-H and N-H bonds do not introduce defect states in the energy gap. The charges are transferred from silicon to nitrogen in the Si-N bond, from silicon to hydrogen in the Si-H bond, and from hydrogen to nitrogen in the N-H bond. The vibrational modes of the Si-H and N-H bonds are calculated and characterized. The net charges of the Si and H atoms in the Si-H bond can influence the Si-H bond stretching frequency. The bare-proton like hydrogen in the N-H bond can couple with the neighboring bonded N atom to form the hydrogen bond, which will decrease the N-H bond stretching frequency.