Impulse approximation Multi-charged ion 6 Cross section 4 Eikonal 4 Electron capture 4 Hydrogen 4 Intermediate energies 4 Monte Carlo methods 4 Atomic hydrogen 2 Atoms 2 Born approximation 2 Capture cross sections 2 Charge transfer 2 Charge-exchange cross sections 2 Classical trajectory monte carlo 2 Classical trajectory monte carlo methods 2 Density matrix elements 2 Electron excitations 2 Electron-capture cross sections 2 Electron-capture process 2 Excitation cross section 2 Excitation process 2 Experiments 2 High energy 2 Hydrogen targets 2 Intermediate energy range 2 Ion bombardment 2 Ion-atom 2 Ions 2 Multipole expansions 2