Multireference CI Gradients and MCSCF Second Derivatives.
Abstract
A set of simple and efficient formulas for the calculation of multireference CI gradients and MCSCF second derivatives is presented. The CI gradient formalism is extended to include a general class of references in the CI. This extension is necessary for the calculation of gradients for a commonly employed class of CI wavefunctions for which the reference configurations are selected from a generalized CAS MCSCF wavefunction. In addition, we report the first general multireference CI gradient calculations. The calculations are for the reaction Be + H2 yields BeH2 constrained to C2v symmetry. Structures of the reactant and transition state and the activation energy calculated at the selected reference CI level compare favorably to the full second order CI results. MCSCF second derivatives are found to be useful for the optimization of the CI structures. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- May 01, 1986
- Accession Number
- ADA170720
Entities
People
- Byron H. Lengsfield Iii
- George F. Adams
- Michael J. Page
- Paul J. Saxe
Organizations
- Ballistic Research Laboratory