First-principle studies of the effects of K vacancy in KDP crystals upon laser-induced damage

This paper presents the ab initio calculations results of K vacancy in KDP crystals. The electronic structures and formation energy as well as the relaxing configuration of K vacancy were detailedly studied. The properties of density of states and band structure on KDP with K vacancy were discussed. The formation energy of K vacancy was calculated to be about 6.5 eV and much lower than that of K interstitial (13.07 eV). The cell parameters increase due to K vacancy and the volume enlargement of cavum surrounded by the neighboring eight O atoms is nearly 3.2%, which is in favor of the transference for K atoms and is benefit for the impurity atoms to fill the cavum in KDP. The increasing of mobility ratio of K induces the increasing of ionic conductivity, therefore laser-induced damage thres