C5H4: Pyramidane and Its Low-Lying Isomers Kenny, Joseph P. ; Krueger, Karl M. ; Rienstra-Kiracofe, Jonathan C. ; Schaefer, Henry F. Abstract Publication: Journal of Physical Chemistry A Pub Date: August 2001 DOI: 10.1021/jp011642r Bibcode: 2001JPCA..105.7745K