Focal point extrapolation procedures

Abstract

The high level of accuracy obtained with present computational chemistry methods is rapidly increasing with faster computing, more efficient codes, and higher levels of theory becoming available for general use. Chemical accuracy is within the field’s grasp for most small molecules. However, some investigations warrant even higher accuracy that that. In this work, the recently implemented coupled cluster with singles, doubles, triples, and perturbative quadruples [CCSDT(Q)] level of theory is exploited under the focal point scheme to attain very accurate properties for the HCCO radical and implications for its further utility are discussed.