The cost of accurate wave function methods can be enormously reduced through combining pair natural orbital techniques and explicitly correlated theory. We present an improved formulation, focusing on second-order Moller-Plesset theory.
Frontiers in Wave Function Theory
Pair natural orbitals in explicitly correlated second-order møller–plesset theory†
Article first published online: 14 APR 2012
Copyright © 2011 Wiley Periodicals, Inc.
International Journal of Quantum Chemistry
Special Issue: Seventh Congress of the International Society for Theoretical Chemical Physics
Volume 113, Issue 3, pages 224–229, 5 February 2013
How to Cite
Tew, D. P. and Hättig, C. (2013), Pair natural orbitals in explicitly correlated second-order møller–plesset theory. Int. J. Quantum Chem., 113: 224–229. doi: 10.1002/qua.24098
- Issue published online: 17 DEC 2012
- Article first published online: 14 APR 2012
- Manuscript Accepted: 29 FEB 2012
- Manuscript Revised: 26 FEB 2012
- Manuscript Received: 15 JAN 2012
- Deutsche Forschungsgemeinschaft; Royal Society (University Research Fellow scheme, D.P.T.)
- explicit correlation;
- pair natural orbitals
An improved formulation of pair natural orbital (PNO)–based explicitly correlated Møller–Plesset second-order perturbation theory is presented. Increased efficiency has been achieved by modifying the representation of the strong orthogonality projector used in the evaluation of the F12 intermediates. We demonstrate two simple relationships between the truncation errors arising from PNOs in the virtual space and those arising from the PNOs in the strong orthogonality operators. This permits robust error control through a single parameter.