Electron capture in ion-atom and ion-molecule collisions is a fundamental collision process in atomic physics related to its application in laboratory and astrophysical plasma environments by affecting the ionization balance and energy transport.Beyond the applications for plasma research,the heavy particle collision processes may drive the fundamental interest in collision dynamics.In the present work,we have carried out the quantum-mechanical molecular orbital close coupling(MOCC)[1] calculations for ion-atom and ion-molecule collisions.The molecular structure data(potential curves,radial and rotational coupling matrix elements)required in the calculations were determined by using the multireference single-and double-excitation configuration interaction(MRDCI)method [2,3] with Gaussian-type basis set.For the ion-atom collisions,the total and state-selective electron capture cross sections were calculated [4].The collision dynamics are discussed in terms of the most important reaction paths and the involved radial and rotational couplings.For ion-molecule collision,the electron capture and collision-induced dissociation processes in H2 ++He collision were calculated [5].The molecular alignment effect was investigated.