Keyword category:

Enhanced Output

BONDS

Description

The bond order between all pairs of atoms is printed. In this context a bond is defined as the sum of the squares of the density matrix elements connecting any two atoms. For ethane, ethylene, and acetylene the carbon-carbon bond orders are roughly 1.00, 2.00, and 3.00 respectively. The diagonal terms are the valences calculated from the atomic terms only and are defined as the sum of the bonds the atom makes with other atoms. This type of analysis is carried out by the Coulson method (see Chapter 16, References for references). In UHF wavefunctions (alpha and beta density matrices) the calculated valence will be somewhat incorrect.

See also:

VECTORS