o: trial function is used to evaluate the upper limit of ground state energy El φ= ground state wave function, JφHψdτ=E1 iii. optimize paramemters in q by minimizing ∫φHφdτ/∫φφdτi. f : trial function is used to evaluate the upper limit of ground state energy E1 ii. f = ground state wave function,  f * H f dt = E1 iii. optimize paramemters in f by minimizing  f * H f dt /  f * f dt