  MCNP6, the latest and most advanced LANL transport code representing a recent
merger of MCNP5 and MCNPX, has been Validated and Verified (V&V) against a
variety of intermediate and high-energy experimental data and against results
by different versions of MCNPX and other codes. In the present work, we V&V
MCNP6 using mainly the latest modifications of the Cascade-Exciton Model (CEM)
and of the Los Alamos version of the Quark-Gluon String Model (LAQGSM) event
generators CEM03.02 and LAQGSM03.03. We found that MCNP6 describes reasonably
well various reactions induced by particles and nuclei at incident energies
from 18 MeV to about 1 TeV per nucleon measured on thin and thick targets and
agrees very well with similar results obtained with MCNPX and calculations by
CEM03.02, LAQGSM03.01 (03.03), INCL4 + ABLA, and Bertini INC + Dresner
evaporation, EPAX, ABRABLA, HIPSE, and AMD, used as stand alone codes. Most of
several computational bugs and more serious physics problems observed in
MCNP6/X during our V&V have been fixed; we continue our work to solve all the
known problems before MCNP6 is distributed to the public.
