Journal
INTERNATIONAL JOURNAL OF QUANTUM CHEMISTRY
Volume 109, Issue 10, Pages 2178-2190Publisher
WILEY
DOI: 10.1002/qua.22099
Keywords
DMRG-CASSCF; multireferencce; strong correlation; carbine; orbital optimization
Categories
Funding
- Cornell University
- Cornell Center for Materials Research (CCMR)
- David and Lucile Packard Foundation
- Alfred P. Sloan Foundation
- Core Research for Evolutional Science and Technology Program
- Japan Science and Technology Agency (JST)
- Research Center for Computational Science, Okazaki Japan
- National Science Foundation CAREER Program [CHE-0645380]
- Department of Energy, Office of Science [DE-FG02-07ER46432]
- Ministry of Education, Culture, Sports, Science and Technology, Japan (MEXT) [461]
Ask authors/readers for more resources
An algorithm that accelerates the convergence of the iterative optimization of the complete active space self-consistent field (CASSCF) wavefunction so as to find a optimum solution in fewer macroiterations is described. The algorithm is oriented to large-scale CASSCF problems that are to be solved with a combination of density matrix renormalization group (DMRG) method for the configuration interaction (CI) process. The algorithm is based on the alternating (or two-step) CASSCF optimization in which the CI and molecular orbital (MO) parameters are optimized separately. Convergence ratio is improved by finding further optimized MOs from a linear extrapolation of the MO sets of the iteration history. The acceleration results in fewer diagonalizations in a total CASSCF calculation to save a considerable computational cost. The convergence performance is examined in a couple of realistic applications on SiC3 and poly (phenyl)carbenes. For poly(phenyl)carbenes, the large-size CASSCF calculations with CAS(30e,30o) that entails full pi valence space as well as sp(2) orbital space of carbenes are performed by using the practical implementation of DMRG-CASSCF in conjunction with the acceleration technique. (C) 2009 Wiley Periodicals, Inc. Int J Quantum Chem 109: 2178-2190, 2009
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available