  We study the fundamental lattice solitons of the discrete nonlinear
Schr\"{o}dinger (DNLS) equation and their stability via a variational method.
Using a Gaussian ansatz and comparing the results with numerical computations,
we report a novel observation of false instabilities. Comparing with
established results and using Vakhitov-Kolokolov criterion, we deduce that the
instabilities are due to the ansatz. In the context of using the same type of
ansatzs, we provide a remedy by employing multiple Gaussian functions. The
results show that the higher the number of Gaussian function used, the better
the solution approximation.
