Higher-order polarizabilities for the helium isoelectronic series

Accurate and explicitly electron-correlated wave functions have been used to calculate the dipole polarizability (α), second hyperpolarizability (γ), dipole–dipole–quadrupole (B), and quadrupole–quadrupole (C) polarizabilities of the helium isoelectronic series He,...,Ne8+. It is believed that our results, which in nearly all cases are new, are very accurate and should serve as a benchmark for future experiments and calculations.