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Short Iterative Lanczos Integration in Time-Dependent Equation-of-Motion Coupled-Cluster Theory
- Source :
- The journal of physical chemistry. A. 125(24)
- Publication Year :
- 2021
-
Abstract
- A time-dependent (TD) formulation of equation-of-motion coupled-cluster (EOM-CC) theory can provide excited-state information over an arbitrarily wide energy window with a reduced memory footprint relative to conventional, frequency-domain EOM-CC theory. However, the floating-point costs of the time-integration required by TD-EOM-CC are generally far larger than those of the frequency-domain form of the approach. This work considers the potential of the short iterative Lanczos (SIL) integration scheme [J. Chem. Phys.1986, 85, 5870-5876] to reduce the floating-point costs of TD-EOM-CC simulations. Low-energy and K-edge absorption features for small molecules are evaluated using TD-EOM-CC with single and double excitations, with the time-integrations carried out via SIL and fourth-order Runge-Kutta (RK4) schemes. Spectra derived from SIL- and RK4-driven simulations are nearly indistinguishable, and with an appropriately chosen subspace dimension, the SIL requires far fewer floating-point operations than are required by RK4. For K-edge spectra, SIL is the more efficient scheme by an average factor of 7.2.
- Subjects :
- Work (thermodynamics)
010304 chemical physics
Chemistry
Equations of motion
010402 general chemistry
01 natural sciences
Spectral line
0104 chemical sciences
Lanczos resampling
Coupled cluster
Dimension (vector space)
0103 physical sciences
Memory footprint
Applied mathematics
Physical and Theoretical Chemistry
Subspace topology
Subjects
Details
- ISSN :
- 15205215
- Volume :
- 125
- Issue :
- 24
- Database :
- OpenAIRE
- Journal :
- The journal of physical chemistry. A
- Accession number :
- edsair.doi.dedup.....b829c7d84f24d39b4b038ecb11e6afd2