Optimized Structure and Vibrational Properties by Error Affected Potential Energy Surfaces.

@article{Zen2012OptimizedSA,
  title={Optimized Structure and Vibrational Properties by Error Affected Potential Energy Surfaces.},
  author={Andrea Zen and D. Zhelyazov and Leonardo Guidoni},
  journal={Journal of chemical theory and computation},
  year={2012},
  volume={8 11},
  pages={
          4204-4215
        }
}
The precise theoretical determination of the geometrical parameters of molecules at the minima of their potential energy surface and of the corresponding vibrational properties are of fundamental importance for the interpretation of vibrational spectroscopy experiments. Quantum Monte Carlo techniques are correlated electronic structure methods promising for large molecules, which are intrinsically affected by stochastic errors on both energy and force calculations, making the mentioned… 

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References

SHOWING 1-10 OF 154 REFERENCES

Structural Optimization by Quantum Monte Carlo: Investigating the Low-Lying Excited States of Ethylene.

The variational convergence of both wave function parameters and atomic positions is presented, demonstrating how Quantum Monte Carlo calculations have become a promising and computationally affordable tool for the structural optimization of correlated molecular systems.

Direct calculation of anharmonic vibrational states of polyatomic molecules using potential energy surfaces calculated from density functional theory

Potential energy surface points computed from variants of density functional theory (DFT) are used to calculate directly the anharmonic vibrational frequencies of H2O, Cl−H2O, and (H2O)2. The method

Fundamental vibrational frequencies of small polyatomic molecules from density-functional calculations and vibrational perturbation theory

An extensive study of fundamental frequencies and anharmonic vibrational constants for polyatomic molecules obtained from Becke three parameter Lee–Yang–Parr (B3LYP) and Becke–Perdew (BP86) density

Ab initio calculation of anharmonic vibrational states of polyatomic systems: Electronic structure combined with vibrational self-consistent field

An algorithm for first-principles calculation of vibrational spectroscopy of polyatomic molecules is proposed, which combines electronic ab initio codes with the vibrational self-consistent field

Alternative perturbation method for the molecular vibration-rotation problem

This article introduces an alternative perturbation scheme to find approximate solutions of the spectral problem for the rotation–vibration molecular Hamiltonian. The method is implemented for the

Ab initio and improved empirical potentials for the calculation of the anharmonic vibrational states and intramolecular mode coupling of N-methylacetamide

The second-order Moller−Plesset ab initio electronic structure method is used to compute points for the anharmonic mode-coupled potential energy surface of N-methylacetamide (NMA) in the transct

Scaling Factors and Uncertainties for ab Initio Anharmonic Vibrational Frequencies.

Scaling factors are reported for anharmonic (second-order perturbation theory) predictions from HF, MP2, and B3LYP calculations using the 6-31G(d) and 6- 31+G( d,p) basis sets.

Weak binding between two aromatic rings: feeling the van der Waals attraction by quantum Monte Carlo methods.

An improved version of the stochastic reconfiguration technique is employed to optimize the many-body wave function, which is the starting point for highly accurate simulations based on the lattice regularized diffusion Monte Carlo method.

Dissecting the Hydrogen Bond: A Quantum Monte Carlo Approach.

The present Quantum Monte Carlo approach based on the JAGP wave function is revealed as a promising tool for the interpretation and the quantitative description of weakly interacting systems, where both dispersive and covalent energy contributions play an important role.
...