An efficient formulation of the analytic energy gradient for the single and double excitation coupled‐cluster method that includes a perturbational estimate of the effects of connected triple excitations, denoted CCSD(T), is presented. The formulation presented here has a smaller computational cost than any previous formulation, and the algebraic manipulations that lead to the additional savings may be applied generally to the analytic gradient of Mo/ller–Plesset perturbation theory energies. The energy contribution from connected triple excitations scales as n3on4v+n4on3v, and the additional work needed for the gradient scales as 2n3on4v+2n4on3v, where no is the number of doubly occupied orbitals and nv is the number of unoccupied orbitals. The new formulation has been implemented in an efficient set of programs that utilize highly vectorized algorithms and has been used to investigate the equilibrium structures, harmonic vibrational frequencies, infrared intensities, and energy separation of cis‐ and trans‐HONO.
Skip Nav Destination
Article navigation
1 May 1991
Research Article|
May 01 1991
Analytic gradients for coupled‐cluster energies that include noniterative connected triple excitations: Application to cis‐ and trans‐HONO
Timothy J. Lee;
Timothy J. Lee
NASA Ames Research Center, Moffett Field, California, 94035
Search for other works by this author on:
Alistair P. Rendell
Alistair P. Rendell
NASA Ames Research Center, Moffett Field, California, 94035
Search for other works by this author on:
J. Chem. Phys. 94, 6229–6236 (1991)
Article history
Received:
December 06 1990
Accepted:
January 18 1991
Citation
Timothy J. Lee, Alistair P. Rendell; Analytic gradients for coupled‐cluster energies that include noniterative connected triple excitations: Application to cis‐ and trans‐HONO. J. Chem. Phys. 1 May 1991; 94 (9): 6229–6236. https://doi.org/10.1063/1.460411
Download citation file:
Sign in
Don't already have an account? Register
Sign In
You could not be signed in. Please check your credentials and make sure you have an active account and try again.
Pay-Per-View Access
$40.00
Citing articles via
A theory of pitch for the hydrodynamic properties of molecules, helices, and achiral swimmers at low Reynolds number
Anderson D. S. Duraes, J. Daniel Gezelter
DeePMD-kit v2: A software package for deep potential models
Jinzhe Zeng, Duo Zhang, et al.
Related Content
Classical dynamics study of HONO using constrained trajectories
J. Chem. Phys. (February 1992)
Computational determination of the S1(Ã1A″) absorption spectra of HONO and DONO using full-dimensional neural network potential energy surfaces
J. Chem. Phys. (July 2024)
Rotational dynamics of nitrous acid (HONO) in Kr matrix
J. Chem. Phys. (July 2008)
The infrared laser photoisomerization of HONO in solid N2 and Ar
J. Chem. Phys. (September 1982)
Intramolecular vibrational energy relaxation in nitrous acid (HONO)
J. Chem. Phys. (October 2008)