VARIATIONAL-PRINCIPLES FOR THE TIME-INDEPENDENT WAVE-PACKET-SCHRODINGER AND WAVE-PACKET-LIPPMANN-SCHWINGER EQUATIONS

Several variational principles, whose Euler equations are the recently derived time-independent wave-packet-Schrodinger or wave-packet-Lippm ann-Schwinger equations, are presented. A particularly attractive wave -packet-Kohn variational principle for either the T- or S-matrix is gi ven which yields inhomogeneous algebraic equations whose ''universal i nhomogeneity'' does not depend explicitly on the collision energy. The validity of the approach is demonstrated with calculations for two si mple one dimensional scattering problems and for the collinear H+H-2 r eactive scattering problem.