Nonperturbative Corrections to One Gluon Exchange Quark Potentials
  The leading nonperturbative QCD corrections to the one gluon exchange quark-quark, quark-antiquark and $q \bar{q}$ pair-excitation potentials are derived by using a covariant form of nonlocal two-quark and two-gluon vacuum expectation values. Our numerical calculation indicates that the correction of quark and gluon condensates to the quark-antiquark potential improves the heavy quarkonium spectra to some degree. 
J.J. Yang, H.Q. Shen, G.L. Li, T. Huang, P.N. Shen