Toward accurate solvation dynamics of lanthanides and actinides in water using polarizable force fields: from gas-phase energetics to hydration free energies

Abstract

In this contribution, we focused on the use of polarizable force fields to model the structural, energetic, and thermodynamical properties of lanthanides and actinides in water. In a first part, we chose the particular case of the Th(IV) cation to demonstrate the capabilities of the AMOEBA polarizable force field to reproduce both reference ab initio gas-phase energetics and experimental data including coordination numbers and radial distribution functions. Using such model, we predicted the first polarizable force field estimate of Th(IV) solvation free energy, which accounts for -1,638 kcal/mol. In addition, we proposed in a second part of this work a full extension of the SIBFA (Sum of Interaction Between Fragments Ab initio computed) polarizable potential to lanthanides (La(III) and Lu(III)) and to actinides (Th(IV)) in water. We demonstrate its capabilities to reproduce all ab initio contributions as extracted from energy decomposition analysis computations, including many-body charge transfer and discussed its applicability to extended molecular dynamics and its parametrization on high-level post-Hartree-Fock data.

Classical Electrostatics for Biomolecular Simulations

“…294,428–430 Previous studies have pointed out that a fixed-charge force field will underestimate the Mg 2+ -guanine interaction energy by as much as 30% due to the absence of the many-body polarization energy. 431 Attempts have been made to model transition metal Zn 2+ , 398,432 lanthanides (Gd 3+ , 433 ) and actinides (Th 2+ , 434 ) with polarizable force fields. Accurate modeling of such high-valence ions with classical mechanics will likely need additional physics beyond polarization, such as charge transfer and ligand-field effects.…”

“…Ren and Ponder have been developing an atomic multipole-based polarizable force field, Atomic Multipole Optimized Energetics for Biomolecular Applications (AMOEBA). After the initial the water model, 298,299,374 this force field has been extended to ions, 398,428–430,434 organic molecules, 297,468–471 and proteins. 272 AMOEBA has been applied in a few studies on the thermodynamics of protein-ligands bindings.…”

Addressing the Issues of Non-isotropy and Non-additivity in the Development of Quantum Chemistry-Grounded Polarizable Molecular Mechanics

“…As reviewed above, SIBFA has been adapted to a diversity of metal cations. These encompass the following: alkali Li(I)-Cs(I) [45], alkaline-earth Mg (II) and Ca(II) [47b], transition metals Cu(I) [62], Cu(II) [44], Zn(II) and Cd(II) [47b, 48, 61], heavy metals Pb(II) [55] and Hg(II) [70], and lanthanides and actinides [122]. Table I.…”

Fragment Molecular Orbital-Based Molecular Dynamics Study on Hydrated Ln(III) Ions

“…So far, an amount of simulations covering classical molecular mechanical (MM) MD, quantum mechanical (QM) and plane-wave type Car-Parrinello MD (CPMD) [16] and hybrid QM/MM MD have been reported on the hydrated Ln(III) ions [17][18][19][20][21][22][23][24][25][26][27][28][29][30][31][32][33][34]. A notable merit of CPMD is that it can directly handle electronic properties [17,18,23,29] at sizable computational costs.…”