Study of tunneling splitting with symmetrically-combined Morse potential model using associated Laguerre basis functions

The one-dimensional symmetrical double-minimum potential is used as the vibrational tunneling splitting model in hydrogen-bonding systems. The vibrational eigenvalue and the system wave functions are calculated both by the Stormer-Levy finite difference method and the variational method, of which basis functions are associated Laguerre functions. It is well known that the former method gives the good approximate values. In the latter method, the accuracy of the solution depends on the number of basis functions. The variational method with some expansion terms is in good agreement with the finite difference method. (C) 2002 Elsevier Science B.V. All rights reserved.