China Ctr Adv Sci & Technol, World Lab, Beijing 100080, Peoples R China
; Acad Sinica, USTC, Grad Sch, Beijing 100039, Peoples R China
; Acad Sinica, Inst Theoret Phys, Beijing 100080, Peoples R China
; Univ Milan, Dept Phys, Ist Nazl Fis Nucl, I-20133 Milan, Italy
; Nankai Univ, Dept Phys, Tianjin 300071, Peoples R China
; Acad Sinica, Inst High Energy Phys, Beijing 100039, Peoples R China
; Natl Lab Heavy Ion Accelerator, Ctr Theoret Nucl Phys, Lanzhou 730000, Peoples R China
In the framework of the nonrelativistic potential model, the variational method, especially the selection of the trial wave function (TWF) is studied via the calculations of energy eigenvalues and wave functions at the origin (WFO) in heavy quarkonium systems. As a result, a more efficient way to construct the TWF is found. With this TWF, the accuracy of the squared WFO can be of the same order as that of the corresponding energy eigenvalue. The relation between the WFO and the reduced mass is also investigated. The resultant formulas agree with those deduced from the general arguments for the power-law potentials. [S0556-2821(99)02213-4].