Quantum proton transfer with spatially dependent friction: Phenol-amine in methyl chloride

In a recent paper [D. Antoniou and S. D. Schwartz, J. Chem. Phys. 110, 465 (1999)] we calculated the reaction rate for a proton transfer reaction in liquid methyl chloride. In that work, we used a spectral density obtained from a molecular dynamics simulation as input to a quantum Zwanzig Hamiltonian which we solved using our exponential resummation method. In the present paper we perform a similar calculation, allowing for a position dependent friction using the method of G. Haynes, G. Voth, and E. Pollak [J. Chem. Phys. 101, 7811 (1994)]. Compared with the results of our previous work, we found that including spatial dependence to the friction led to enhancement of the reaction rate and to reduction of the H/D kinetic isotope effect. (C) 1999 American Institute of Physics. [S0021-9606(99)51715-7].