Perspective: Computing (ro-)vibrational spectra of molecules with more than
          four atoms

Carrington, Tucker

doi:10.1063/1.4979117

Cited by 97 publications

(76 citation statements)

References 148 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Furthermore, the two monomers need to be coupled together and with the pair modes. It is important to build on the good VPT2 performance for the pair modes as test cases for alternative, presumably mostly variational methods 48,[92][93][94] , which reach further up on the energy scale. It may be too ambitious to aim at a quantitative description of the complex coupling pattern in the OH stretching region 36,41,[95][96][97] , but the more isolated couplings in the monomer fingerprint up to the carbonyl stretching region 81 are waiting to be understood in detail for FAD.…”

Section: Future Challengesmentioning

confidence: 99%

Concerted Pair Motion Due to Double Hydrogen Bonding: The Formic Acid Dimer Case

Nejad

Suhm

2019

J Indian Inst Sci

View full text Add to dashboard Cite

| Formic acid dimer as the prototypical doubly hydrogenbonded gas-phase species is discussed from the perspective of the three translational and the three rotational degrees of freedom which are lost when two formic acid molecules form a stable complex. The experimental characterisation of these strongly hindered translations and rotations is reviewed, as are attempts to describe the associated fundamental vibrations, their combinations, and their thermal shifts by different electronic structure calculations and vibrational models. A remarkable match is confirmed for the combination of a CCSD(T)-level harmonic treatment and an MP2-level anharmonic VPT2 correction. Qualitatively correct thermal shifts of the vibrational spectra can be obtained from classical molecular dynamics in CCSD(T)-quality force fields. A detailed analysis suggests that this agreement between experiment and composite theoretical treatment is not strongly affected by fortuitous error cancellation but fully converged variational treatments of the six pair or intermolecular modes and their overtones and combinations in this model system would be welcome.

show abstract

Section: Future Challengesmentioning

confidence: 99%

Concerted Pair Motion Due to Double Hydrogen Bonding: The Formic Acid Dimer Case

Nejad

Suhm

2019

J Indian Inst Sci

View full text Add to dashboard Cite

show abstract

“…[81] Geometric isotope effects (GIEs), on the other hand, can be retrieved by solving a nuclear Schrödinger equation that considers the anharmonicity of the nuclear potential. [82][83][84] These calculations are usually carried out employing the vibrational self-consistent field method [85] or grid based approaches such as the discrete variable representation. [86][87][88][89] Alternatively, GIEs can be analyzed performing path integral molecular dynamics simulations.…”

Section: Isotope Effectsmentioning

confidence: 99%

The any particle molecular orbital approach: A short review of the theory and applications

Reyes

Moncada

Charry

2018

Int J of Quantum Chemistry

View full text Add to dashboard Cite

The any particle molecular orbital (APMO) approach extends regular electronic structure methods to study atomic and molecular systems in which electrons and other particles are treated simultaneously as quantum waves. A number of electronic structure methodologies have been extended under the APMO framework and applied to investigate nuclear quantum effects including isotope effects and nuclear delocalization and to calculate proton binding energies and affinities. In addition, APMO methodologies have been employed to analyze physical and chemical properties of atomic and molecular systems containing exotic subatomic particles.

show abstract

“…In recent years collocation has been used to compute vibrational spectra of small polyatomic molecules. [1][2][3][4][5][6][7][8][9] To use collocation, one demands that a basis representation of solutions to the Schrödinger equation exactly satisfies the Schrödinger equation at a set of collocation points. In a collocation calculation, the potential matrix is diagonal, but the collocation eigenvalue problem is not the same as the eigenvalue problem solved when using a discrete variable representation (DVR).…”

Section: Introductionmentioning

confidence: 99%

Using collocation and a hierarchical basis to solve the vibrational Schrödinger equation

Żak

Carrington

2019

The Journal of Chemical Physics

Self Cite

View full text Add to dashboard Cite

We show that it is possible to compute vibrational energy levels of polyatomic molecules with a collocation method and a basis of products of one-dimensional harmonic oscillator functions pruned so that it does not include functions for which the indices of many of the one-dimensional functions are non-zero. Functions with many non-zero indices are coupled only by terms that depend simultaneously on many coordinates and they are typically small. The collocation equation is derived without invoking differences of interpolation operators, which simplifies implementation of the method. This, however, requires inverting a matrix whose elements are values of the pruned basis functions at the collocation points. The collocation points are the points on a Smolyak grid whose size is equal to the size of the pruned basis set.The Smolyak grid is built from symmetrized Leja points. Because both the basis and the grid are not tensor products, the inverse is not straightforward. It can be done by using so-called hierarchical 1-D basis functions. They are defined so that the matrix whose elements are the 1-D hierarchical basis functions evaluated at points is lower triangular. We test the method by applying it to compute 100 energy levels of CH 2 NH with an iterative eigensolver. a)

show abstract

Perspective: Computing (ro-)vibrational spectra of molecules with more than four atoms

Cited by 97 publications

References 148 publications

Concerted Pair Motion Due to Double Hydrogen Bonding: The Formic Acid Dimer Case

Concerted Pair Motion Due to Double Hydrogen Bonding: The Formic Acid Dimer Case

The any particle molecular orbital approach: A short review of the theory and applications

Using collocation and a hierarchical basis to solve the vibrational Schrödinger equation

Contact Info

Product

Resources

About