pmvt and
  qmvt functions from the mvtnorm package. Note that
  always the "GenzBretz" algorithm is used, as only this allows for
  calculating multivariate t-distribution integrals. See the
  mvtnorm documentation for more information.mvtnorm.control(maxpts = 30000, abseps = 0.001, releps = 0,
           interval = NULL)pmvt, qmvt