Ever since establishment of the 'cold fusion' phenomenon, many attempts are
made to explain its origin. Barut and Vigier [1] suggested that the observ
ed 'excess heat' in cold fusion experiments could be related to the new tig
htly bound states of the hydrogen atom. These states are due to electromagn
etic interactions at small distances. Another mechanism for the occurrence
of deep energy levels could be a creation of the 'anti-Born-Oppenheimer' st
ates, corresponding Co rapid motion of the heavy particles around almost fi
xed electrons. Both possibilities are reviewed in this Letter. (C) 2000 Els
evier Science B.V. All rights reserved.