Attosecond electron dynamics with linear combination of floating gaussian type basis function

A new approach to electron dynamics in molecular system is developed, which combines ab initio molecular orbital (MO) scheme and Gaussian wave packet dynamics. The time-dependent electronic wavefunction is described by the linear combination of atomic orbitals (LCAO) using frozen-width floating Gaussian wave packet basis functions. The equations of motion for the time-dependent variables, such as the LCAO coefficients, the Gaussian centers, and their phase factors of the respective basis functions, are determined based on time-dependent variational principle. This technique is demonstrated for the attosecond propagation of electronic wavefunction of hydrogen and helium atoms in response to electrostatic field.