ACAD SINICA,GRAD SCH,BEIJING 100039,PEOPLES R CHINA
; ACAD SINICA,INST THEORET PHYS,BEIJING 100080,PEOPLES R CHINA
; NANKAI UNIV,DEPT PHYS,TIANJIN 300071,PEOPLES R CHINA
; ACAD SINICA,INST HIGH ENERGY PHYS,BEIJING 100039,PEOPLES R CHINA
; UNIV ADELAIDE,DEPT PHYS & MATH PHYS,ADELAIDE,SA 5001,AUSTRALIA
The Cornell potential with the best fitted parameters alpha(s) and kappa are modified by adding terms derived from nouperturbative QCD, which are characterized by a series of nonvanishing vacuum condensates of quarks and gluons. In terms of this potential, we study the system of heavy quarkonia. The results show that the correction caused by the additional terms reduces the deviation between the data and the values calculated with the pure Cornell potential and improves the splittings of energy levels. The achievements indicate that the nonperturbative effects induced by vacuum condensates play an important role for the correction to 1/q(2), which in general was phenomenologically put in by hand. This result would be helpful for understanding nonperturbative QCD along a parallel direction to the QCD sum rules.