Contents list for Physical Chemistry Chemical Physics, issue 23, 2008
Explicit-r12 correlation methods and local correlation methods
Phys. Chem. Chem. Phys., 2008, 10, 3318
There have been many recent improvements in computational methods for solving the infamous electron correlation problem. This Editorial introduces the papers in this Themed Issue by putting them into a broader perspective.
Front and Back Matter
Implementation of the CCSD(T)-F12 method using cusp conditions
Denis Bokhan, Seiichiro Ten-no and Jozef Noga, Phys. Chem. Chem. Phys., 2008, 10, 3320
The CCSD(T)-F12 method using cusp conditions gives theoretical enthalpies of 13 isogyric chemical reactions accurate to 2 kJ mol-1.
Analysis of non-covalent interactions in (bio)organic molecules using orbital-partitioned localized MP2
Stefan Grimme, Christian Mück-Lichtenfeld and Jens Antony, Phys. Chem. Chem. Phys., 2008, 10, 3327
Inter-molecular or inter-fragment pair correlation contributions aggregated as –, –, –, etc. are investigated. They are representative of the mode of interaction and the breakdowns are transferrable. This approach yields important insight into non-covalent interactions also regarding the accuracy of the MP2 method.
Tighter multipole-based integral estimates and parallel implementation of linear-scaling AO–MP2 theory
Bernd Doser, Daniel S. Lambrecht and Christian Ochsenfeld, Phys. Chem. Chem. Phys., 2008, 10, 3335
Optimized screening criteria for preselecting numerically significant contributions and parallelization allow for large-scale linear-scaling AO–MP2 calculations with large basis sets. The largest system calculated so far is a 16 base-pair DNA strand with 1052 atoms and 10674 basis functions.
Local correlation domains for coupled cluster theory: optical rotation and magnetic-field perturbations
Nicholas J. Russ and T. Daniel Crawford, Phys. Chem. Chem. Phys., 2008, 10, 3345
Canonical and localized bonding orbitals of (1R,4S)-methylnorbornanone and the magnetic coupled-perturbed Hartree–Fock-based domain selection scheme for local-coupled-cluster theory.
Local and density fitting approximations within the short-range/long-range hybrid scheme: application to large non-bonded complexes
Erich Goll, Thierry Leininger, Frederick R. Manby, Alexander Mitrushchenkov, Hans-Joachim Werner and Hermann Stoll, Phys. Chem. Chem. Phys., 2008, 10, 3353
A coupling of short-range DFT with long-range MP2 and CCSD(T) has been efficiently implemented, with density fitting and local correlation.
Equations of explicitly-correlated coupled-cluster methods
Toru Shiozaki, Muneaki Kamiya, So Hirata and Edward F. Valeev, Phys. Chem. Chem. Phys., 2008, 10, 3358
Computerized derivations and algebraic transformations of explicitly-correlated coupled-cluster singles, doubles, triples and quadruples for the ground and excited states.
Diffusion quantum Monte Carlo calculations are presented for several vanadium oxide molecules.
Second-order Møller–Plesset calculations on the water molecule using Gaussian-type orbital and Gaussian-type geminal theory
Pål Dahle, Trygve Helgaker, Dan Jonsson and Peter R. Taylor, Phys. Chem. Chem. Phys., 2008, 10, 3377
The performance of the MP2-GGn model is analyzed and compared with other methods, based on highly accurate calculations on water.
A class of doubly excited electronic states of the hydrogen molecule is reported.
Slater-type geminals in explicitly-correlated perturbation theory: application to n-alkanols and analysis of errors and basis-set requirements
Sebastian Höfener, Florian A. Bischoff, Andreas Glöß and Wim Klopper, Phys. Chem. Chem. Phys., 2008, 10, 3390
A reference study of subtle isomer energy differences in linear alcohols which explores the MP2 basis set limit using nonlinear r12 theory. The main emphasis is on efficient technical approximations and their relative merits.
Accurate calculations of intermolecular interaction energies using explicitly correlated wave functions
Oliver Marchetti and Hans-Joachim Werner, Phys. Chem. Chem. Phys., 2008, 10, 3400
New explicitly correlated electron correlation methods are used to compute intermolecular interaction energies with unprecedented accuracy at moderate cost.
Variational formulation of perturbative explicitly-correlated coupled-cluster methods
Martin Torheyden and Edward F. Valeev, Phys. Chem. Chem. Phys., 2008, 10, 3410
A simple zero-parameter perturbative R12 correction to the CCSD(T) method attains chemical accuracy for reaction energies with only a triple-zeta basis.
Resolution of the identity atomic orbital Laplace transformed second order Møller–Plesset theory for nonconducting periodic systems
Artur F. Izmaylov and Gustavo E. Scuseria, Phys. Chem. Chem. Phys., 2008, 10, 3421
A resolution of identity scheme for periodic AO-LT-MP2 calculations is reported and and examples given for applications on trans-polyacetylene and trans-polymethineimine, as a step forward in the development of ab initio methods for periodic systems.
On the use of the Laplace transform in local correlation methods
Danylo Kats, Denis Usvyat and Martin Schütz, Phys. Chem. Chem. Phys., 2008, 10, 3430
A new local MP2 method based on the Laplace identity is presented and its relation to the original local MP2 is elucidated. The new method corresponds to a least-squares minimization of the canonical residual within the local subspace.
Intracule densities in the strong-interaction limit of density functional theory
Paola Gori-Giorgi, Michael Seidl and Andreas Savin, Phys. Chem. Chem. Phys., 2008, 10, 3440
Be atom: probability distribution for the interelectronic distance when the electronic interaction is multiplied by at fixed one-electron density.
Intracule functional models
Part III. The dot intracule and its Fourier transform
Yves A. Bernard, Deborah L. Crittenden and Peter M. W. Gill, Phys. Chem. Chem. Phys., 2008, 10, 3447
Dot intracules of the HF, H2O, NH3 and CH4 molecules, relative to the Ne atom.
We present Lagrangians which, when minimised, yield the optimal DMRG wavefunction in a variational sense, within the general matrix product ansatz and within the canonical form of the matrix product.
The principle-quantum-number (and the radial-quantum-number) expansion of the correlation energy of two-electron atoms
Werner Kutzelnigg, Phys. Chem. Chem. Phys., 2008, 10, 3460
The second-order correlation energy of two-electron ions is studied in terms of an expansion in minimal approximations to the first-order natural orbitals (NOs). The non-linear parameters of these NOs are determined by minimization of the second-order energy.