Characteristic polynomials of linear polyacenes and their subspectrality

Coefficients of characteristic polynomials (CP) of linear polyacenes (LP) h ave been shown to be obtainable from Pascal's triangle by using a graph fac torisation and squaring technique. Strong subspectrality existing among the members of the linear polyacene series has been shown from the derivation of the CP's. Thus it has been shown that the entire eigenspectrum of an n-r ing LP is included in that of (2n + 1)-ring LP. Correspondence between the eigenspectra of linear chains and LP's is brought out by a recently develop ed vertex-alternation and squaring algorithm.