question on resonance structures

From: sergiusz.kwasniewski(-(at)-)luc.ac.be
Subject: question on resonance structures
Date: Thu, 27 Mar 2003 13:38:51 +0100

Hi,
 As you know, poly-acetylene has a doubly degenerate ground state structure,
 because of the Peierls distortion. The skelet structures can be seen in terms
 of bond alternations as struct1 = (=-=-=)n and struct2 = (-=-=-)n. They both
 consist of a linear combination of partial wavefunctions describing
 wave1 = (=-=-=)n and wave2 = (-=-=-)n (in VB theory).
 If I'm not mistaken wave1 and wave2 are resonance (canonics ?) structures and
 should therefore be written as wave1 <--> wave2. On the other hand,
 struct1
 and struct2 are different molecular structures and they should therefore be
 written as struct1 <==> (i.e. as a chemical equilibrium). I believe these
 structures are called bondisomers.
 Each of these structures can thus be given by A*wave1+B*wave2.
 I would like your opinion on this and would like to get advise on the accurate
 nomenclature of structs and waves.
 I will summerize
 Thanks
 Serge