Ab initio molecular dynamics
Rodolphe Pollet
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The study of chemical properties of molecular complexes in solution or at interfaces cannot ignore the quantum nature of electrons. Ab initio molecular dynamics (e.g., of the Car-Parrinello type) must then supersedes classical simulations. Examples of our contributions in this field are the development of pseudopotentials associated with a plane waves basis set and the calculation of free-energy profiles.

For example, calculations on lanthanides complexes can only be accurate if the 4f electrons are part of the valence space. Moreover, the small extent of these 4f orbitals around the nucleous calls for ultrasoft pseudopotentials in order to reduce the computational cost. We have thus constructed such a (Vanderbilt's) pseudopotential for the gadolinium atom using the PBE exchange-correlation density functional.

As the official version of the CPMD program does not allow Vanderbilt's pseudopotentials with electrons in the f channel (because the Clebsch-Gordan coefficients are tabulated up to the d angular momentum), we use our own development version.

R. Pollet, C. Clavaguéra, and J.-P. Dognon. Ultrasoft pseudopotentials for lanthanide solvation complexes: Core or valence character of the 4f electrons. J. Chem. Phys. 2006, 124, 164103.
Ab initio molecular dynamics

4f AE (solid) and pseudized (circles) radial wave functions (times r) of Gd2+ (ground state electronic configuration), with a cutoff radius equal to 2.0 a.u.

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#598 - Last update : 05/16 2006

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