  We report a new technique to determine the van der Waals coeffcients of
lithium (Li) atoms based on the relativistic coupled-cluster theory. These
quantities are determined using the imaginary parts of the scalar dipole and
quadrupole polarizabilities, which are evaluated using the approach that we
have proposed in [1]. Our procedure is fully ab initio, and avoids the
sum-over-the-states method. We present the dipole and quadrupole
polarizabilities of many of the low-lying excited states of Li. Also, the
off-diagonal dipole and quadrupole polarizabilites between some of the
low-lying states of Li are calculated.
