Generalized valence bond wave functions in quantum Monte Carlo
Abstract
We present a technique for using quantum Monte Carlo (QMC) to obtain high quality energy differences. We use generalized valence bond (GVB) wave functions, for an intuitive approach to capturing the important sources of static correlation, without needing to optimize the orbitals with QMC. Using our modifications to Walker branching and Jastrows, we can then reliably use diffusion quantum Monte Carlo to add in all the dynamic correlation. This simple approach is easily accurate to within a few tenths of a kcal/mol for a variety of problems, which we demonstrate for the adiabatic singlet-triplet splitting in methylene, the vertical and adiabatic singlet-triplet splitting in ethylene, 2+2 cycloaddition, and Be_2 bond breaking.
Additional Information
© 2010 American Institute of Physics. Received 31 August 2009; accepted 10 March 2010; published online 26 April 2010. We wish to thank the reviewer who pointed out that some error in our CAS wave functions is likely the result of CI coefficient optimization without orbital optimization. We also wish to thank Dan Fisher for his contributions to the software, as well as useful discussions.Attached Files
Published - Anderson2010p9989The_Journal_of_chemical_physics.pdf
Files
| Name | Size | Download all |
|---|---|---|
|
md5:a577a5e3ade889110da1beaa59b1f3db
|
402.8 kB | Preview Download |
Additional details
- Eprint ID
- 18311
- Resolver ID
- CaltechAUTHORS:20100514-133918748
- Created
-
2010-05-14Created from EPrint's datestamp field
- Updated
-
2021-11-08Created from EPrint's last_modified field
- Other Numbering System Name
- WAG
- Other Numbering System Identifier
- 0862