Molecular dichotomy within an intense high-frequency laser field

It is shown that, under an intense high-frequency laser field, electronic distributions in molecules exhibit a dichotomy effect just as previously found in atoms. The generalization of the formal demonstration of the dichotomy effect as given in M. Gavrila and J. Shertzer, Phys. Rev. A 41, 477 (1990) to many-electron, polyatomic molecules is considered and the validity of the alpha(0)(-2/3) scaling law of the Floquet eigenvalues, with respect to the field intensity parameter alpha(0) of the HFFT, is discussed. To test the molecular dichotomy effect, numerical calculations are performed using a quantum chemical package (Gaussian 94), modified appropriately to incorporate the cycle-averaged displacements of the nuclear-electron Coulomb potential as found in the HFFT hamiltonian. Results of calculations on the two-electron H-2 molecule are presented with an emphasis placed on the character of the total and orbital charge distributions and on trends to be observed in the electronic correlation at high intensities. (C) 2000 American Institute of Physics. [S0021-9606(00)03003-8].