Legal provisions for optional referendums at national level

Guatemala
Answer
No
Source
Political Constitution of Guatemala (Constitución Política de la República de Guatemala) (1985 with amendments in 1993)http://www.constitutionnet.org/files/Guatemala%20Constitution.pdf
Electoral Code (Ley Electoral y de Partidos políticos) http://hablandoguatemala.files.wordpress.com/2011/01/ley-electoral-y-de-partidos-politicos-de-guatemala3.pdf
Comment
No provision was found in this regard