Communication: Analytic gradients for the complex absorbing potential equation-of-motion coupled-cluster method

Benda, Zsuzsanna and Jagau, Thomas-C. (2017): Communication: Analytic gradients for the complex absorbing potential equation-of-motion coupled-cluster method. In: Journal of Chemical Physics, Vol. 146, No. 3, 31101

Abstract

The general theory of analytic energy gradients is presented for the complex absorbing potential equation-of-motion coupled-cluster (CAP-EOM-CC) method together with an implementation within the singles and doubles approximation. Expressions for the CAP-EOM-CC energy gradient are derived based on a Lagrangian formalism with a special focus on the extra terms arising from the presence of the CAP. Our implementation allows for locating minima on high-dimensional complex-valued potential energy surfaces and thus enables geometry optimizations of resonance states of polyatomic molecules. The applicability of our CAP-EOM-CC gradients is illustrated by computations of the equilibrium structures and adiabatic electron affinities of the temporary anions of formaldehyde, formic acid, and ethylene. The results are compared to those obtained from standard EOM-CC calculations and the advantages of CAP methods are emphasized. Published by AIP Publishing.

• Item Type: Journal article
• Faculties: Chemistry and Pharmacy > Department of Chemistry
• Subjects: 500 Science > 540 Chemistry
• ISSN: 0021-9606
• Language: English