Computed Bond Lengths and Angles

Computational Organic Chemistry, Second Edition. Steven M. Bachrach 2014 John Wiley Sons, Inc. Published 2014 by John Wiley Sons, Inc. 

TABLE 2.1 Comparison of Computed and Experiment Bond Lengths (r. A)  

Cmpd Bond MP2 6-31G TZ2P-l-f B3LYP 6-3IG CCSD TZ2P-Ef Expt 

TABLE 2.2 Mean Absolute Error in Computed Versus Experimental Equilibrium  

Oftentimes one can use a quite resource-efficient method to obtain excellent geometries. Sequential ethynyP or cyano substitution of benzene leads to a systematic increase in the mean bond length within the ring. As seen in Table 2.3, quite excellent reproduction of this trend, and the bond distances themselves, can be had with even B3LYP/6-31G.  

---