Using Electronic Energy Derivative Information in Automated Potential Energy Surface Construction for Vibrational Calculations

Sparta, Manuel
Hansen, Mikkel B.
Matito, Eduard
Toffolı, Danıele
Christiansen, Ove
The availability of an accurate representation of the potential energy surface (PES) is an essential prerequisite in an anharmonic vibrational calculation. At the same time, the high dimensionality of the fully coupled PES and the adverse scaling properties with respect to the molecular size make the construction of an accurate PES a computationally demanding task. In the past few years, our group tested and developed a series of tools and techniques aimed at defining computationally efficient, black-box protocols for the construction of PESs for use in vibrational calculations. This includes the definition of an adaptive density-guided approach (ADGA) for the construction of PESs from an automatically generated set of evaluation points. Another separate aspect has been the exploration of the use of derivative information through modified Shepard (MS) interpolation/extrapolation procedures. With this article, we present an assembled machinery where these methods are embedded in an efficient way to provide both a general machinery as well as concrete computational protocols. In this framework we introduce and discuss the accuracy and computational efficiency of two methods, called ADGA[2gx3M] and ADGA[2hx3M], where the ADGA recipe is used (with MS interpolation) to automatically define modest sized grids for up to two-mode couplings, while MS extrapolation based on, respectively, gradients only and gradients and Hessians from the ADGA determined points provides access to sufficiently accurate three-mode couplings. The performance of the resulting potentials is investigated in vibrational coupled cluster (VCC) calculations. Three molecular systems serve as benchmarks: a trisubstituted methane (CHFClBr), methanimine (CH2NH), and oxazole (C3H3NO). Furthermore, methanimine and oxazole are addressed in accurate calculations aiming to reproduce experimental results.


Potential Energy Surfaces for Vibrational Structure Calculations from a Multiresolution Adaptive Density-Guided Approach: Implementation and Test Calculations
Sparta, Manuel; Hoyvik, Ida-Marie; Toffolı, Danıele; Christiansen, Ove (American Chemical Society (ACS), 2009-07-30)
A multiresolution procedure to construct potential energy surfaces (PESs) for use in vibrational structure calculations is developed in the framework of the adaptive density-guided approach. The implementation of the method allows the construction of hybrid PESs with different mode-coupling terms calculated with a variety of combinations of electronic structure methods and basis sets. Furthermore, the procedure allows the construction of hybrid PESs that incorporate a variety of contributions and correction...
A hierarchy of potential energy surfaces constructed from energies and energy derivatives calculated on grids
Matito, Eduard; Toffolı, Danıele; Christiansen, Ove (AIP Publishing, 2009-04-07)
In this work we develop and test a methodology for the generation of Born-Oppenheimer potential energy surfaces (PES) for use in vibrational structure calculations. The method relies on the widely used restricted-mode-coupling expansion of the fully coupled potential surface where only up to n or less vibrational coordinates are coupled in the potential. Low-order derivatives of the energy are then used to extrapolate the higher mode-coupling potential terms; derivative information is thus used in a conveni...
On the SmCo Dimer: A Detailed Density Functional Theory Analysis
Oymak, Hueseyin; Erkoç, Şakir (American Chemical Society (ACS), 2010-02-04)
Making use of 21 different exchange-correlation functionals, we performed density functional theory calculations, within the effective core potential level, to investigate some spectroscopic and electronic features of the SmCo dimer in its ground state. A particular emphasis was placed on the (spin) multiplicity of SmCo. Most of the functionals under discussion unanimously agreed that the multiplicity of SmCo should be 10. It was observed that the nature of interaction between Sm and Co atoms to form the Sm...
Vibrational spectroscopy of hydrogen-bonded systems: Six-dimensional simulation of the IR spectrum of F-(H2O) complex
Toffolı, Danıele; Sparta, Manuel; Christiansen, Ove (Elsevier BV, 2011-06-24)
The vibrational dynamics of the F-(H2O) complex is studied using highly accurate six-dimensional molecular potential energy and dipole moment surfaces calculated at the CCSD (T)/cc-pVQZ and CCSD (T)/augcc-pVTZ levels with a multiresolution approach. The extent of mode-coupling is investigated with full vibrational configuration-interaction (FVCI) calculations. Coriolis coupling effects are also included with the aim to obtain quantitative agreement with the experimental data available. The vibrational absor...
Empirical many-body potential energy function for silver and gold: Application to microclusters
Erkoc, Sevilay (Elsevier BV, 1990-9)
A recently developed empirical many-body potential energy function (PEF) has been modified and parametrized for the elements silver and gold. The PEF comprises two- and three-body atomic interactions, which satisfy both the bulk cohesive energy per atom and the bulk stability exactly, and give the bulk modulus reasonably well. The structural stability and energetics of microclusters of these elements containing three to seven atoms have been investigated. It has been found that the triangular form of trimer...
Citation Formats
M. Sparta, M. B. Hansen, E. Matito, D. Toffolı, and O. Christiansen, “Using Electronic Energy Derivative Information in Automated Potential Energy Surface Construction for Vibrational Calculations,” JOURNAL OF CHEMICAL THEORY AND COMPUTATION, pp. 3162–3175, 2010, Accessed: 00, 2020. [Online]. Available: