Accurate thermochemistry for molecules containing heavy p-block elements using local explicitly correlated ab initio methods

• Applicant: Professor Dr. Hans-Joachim Werner
• Subject Area: Physical Chemistry of Molecules, Liquids and Interfaces, Biophysical Chemistry
• Term: from 2007 to 2012
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 52486322

• Final Report Year: 2012

Final Report Abstract

The accurate determination of molecular thermochemical properties can greatly influence a wide variety of chemical application areas from materials science to biological chemistry. Over the last several years, it has been demonstrated that ab initio computational thermochemistry has the potential to predict thermochemical quantities to within chemical accuracy, i.e., 4 kJ/mol, and in some cases even into the 1 kJ/mol range. For the most part, however, the treatments employing accurate methods have focused only on elements from the first two rows of the periodic table. In this project have developed a standard methodology, without resort to empirical parameters, for obtaining similarly accurate quantities for chemistry involving the remainder of the p-block elements. The novel aspects of this work are threefold: (i) newly developed explicitly correlated methods, e.g., MP2-F12 and CCSD(T)-F12, are utilized to minimize the substantial errors that can arise from the slow convergence of the 1-particle basis set, (ii) scalar and spin-orbit relativistic effects, which are of crucial importance in these systems, are recovered using carefully benchmarked relativistic effective core potentials (ECPs), and (iii) new systematically convergent basis sets for F12 methods in conjunction with ECPs have been developed as part of this work. Furthermore, in closely related work we have developed explicitly correlated local coupled cluster methods that extend the applicability of these high-level electronic structure methods to molecules with up to about 100 atoms.

Publications

• Extrapolating explicitly correlated correlation energies to the complete basis set limit with first and second row correlation consistent basis sets. Journal of Chemical Physics, Vol. 131. 2009, Issue 19, 194105.
  J. G. Hill, K. A. Peterson, G. Knizia, and H. J. Werner
  (See online at https://dx.doi.org/10.1063/1.3265857)
• An explicitly correlated local coupled cluster method for calculations of large molecules close to the basis set limit. Journal of Chemical Physics, Vol. 135. 2011, Issue 14, 144117.
  T. B. Adler and H.-J. Werner
  (See online at https://dx.doi.org/10.1063/1.3647565)
• Application of explicitly correlated coupled cluster methods to molecules containing post-3d main group elements. Molecular Physics: An International Journal at the Interface Between Chemistry and Physics, Vol. 109. 2011, Issue 22, pp. 2607-2623.
  K. A. Peterson, C. Krause, H. Stoll, J. G. Hill, and H.-J. Werner
  (See online at https://dx.doi.org/10.1080/00268976.2011.624129)
• Explicitly correlated coupled cluster methods with pair-specific geminals. Molecular Physics: An International Journal at the Interface Between Chemistry and Physics, Vol. 109. 2011, Issue 3, pp. 407-417.
  H.-J. Werner, G. Knizia, and F. R. Manby
  (See online at https://dx.doi.org/10.1080/00268976.2010.526641)