The WIMPER (n) approximation is: ln(s/s') f = ln(s/s') f

Correlation of the Isotope Chemistry of Hydrogen, Carbon, and Oxygen with Molecular Forces by the Wimper (2) Method, The Journal of Chemical Physics, 74, 1799 (1975).

Professor Ishida conducted theoretical research on the correlation of isotope chemistry with molecular structure and molecular forces. He studied the chemical and physical effects of stable isotope substitutions in molecules and the separation of stable isotopes.