Use of simulated infrared spectra to test N2-Ar pair potentials and dipole moment surfaces

Wang, Feng

doi:10.1080/00268979609482457

Cited by 15 publications

(22 citation statements)

References 2 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…For normal molecules, the ZPE, which is the energy at ( v = 0), can be very small as shown in the tables. However, for weakly bound systems, such as van der Waals complexes46–48 the ZPE is significantly large, and therefore must be considered when ordering the stability of the minimum structures of the species 48. For this reason, we also produced the ZPE as a “spectroscopic constant” in this study.…”

Section: Resultsmentioning

confidence: 99%

Prediction of spectroscopic constants for diatomic molecules in the ground and excited states using time‐dependent density functional theory

Falzon¹,

Chong²,

Wang³

2005

J Comput Chem

Self Cite

View full text Add to dashboard Cite

Spectroscopic constants of the ground and next seven low-lying excited states of diatomic molecules CO, N2, P2, and ScF were computed using the density functional theory SAOP/ATZP model, in conjunction with time-dependent density functional theory (TD-DFT) and a recently developed Slater type basis set, ATZP. Spectroscopic constants, including the equilibrium distances r(e), harmonic vibrational frequency omega(e), vibrational anharmonicity omega(e)x(e), rotational constant B(e), centrifugal distortion constant D(e), the vibration-rotation interaction constant alpha(e), and the vibrational zero-point energy E(n)0 were generated in an effort to establish a reliable database for electron spectroscopy. By comparison with experimental values and a similar model with an established larger Slater-type basis set, et-QZ3P-xD, it was found that this model provides reliably accurate results at reduced computational costs, for both the ground and excited states of the molecules. The over all errors of all eight lowest lying electronic states of the molecules under study using the effective basis set are r(e)(+/-4%), omega(e)(+/-5% mostly without exceeding +/-20%), omega(e)x(e)(+/-5% mostly without exceeding 20%, much more accurate than a previous study on this constant of +/-30%), B(e)(+/-8%), D(e)(+/-10%), alpha(e)(+/-10%), and E(n)0(+/-10%). The accuracy obtained using the ATZP basis set is very competitive to the larger et-QZ3P-xD basis set in particular in the ground electronic states. The overall errors in r(e), omega(e)x(e), and alpha(e) in the ground states were given by +/-0.7, +/-10.1, and +/-8.4%, respectively, using the efficient ATZP basis set, which is competitive to the errors of +/-0.5, +/-9.2, and +/-9.1%, respectively for those constants using the larger et-QZ3P-xD basis set. The latter basis set, however, needs approximately four times of the CPU time on the National Supercomputing Facilities (Australia). Due to the efficiency of the model (TD-DFT, SAOP and ATZP), it will be readily applied to study larger molecular systems.

show abstract

Section: Resultsmentioning

confidence: 99%

Prediction of spectroscopic constants for diatomic molecules in the ground and excited states using time‐dependent density functional theory

Falzon¹,

Chong²,

Wang³

2005

J Comput Chem

Self Cite

View full text Add to dashboard Cite

show abstract

“…This implies that the former is more realistic than the latter, at least in the potential well region to which this property is most sensitive. When our previous comprehensive simulations of the mid-IR spectrum of 14 N 2 -Ar were in press, a new moderately high resolution far-IR spectrum of N 2 -Ar at Tϭ89 K was reported by Wishnow et al 3 Some features of that spectrum are intriguingly similar to those of the far-IR spectrum we had predicted with a simulation temperature of Tϭ77 K. 5 The objectives of the present work are therefore threefold. First, to test potential and dipole moment surfaces against the new far-IR data; this requires simulations to be performed for the correct temperature using the correct spectral resolution averaging.…”

Section: Introductionmentioning

confidence: 56%

“…For a complex such as N 2 -Ar, with a relatively large reduced mass and a moderately deep potential well, such calculations are tedious and computationally expensive. 4,5 Very few realistic simulations of unresolved IR spectra of van der Waals molecules have thus far been carried out. The earliest were those for N 2 -Ar reported by Ayllón et al, 4 whose results first demonstrated the feasibility of generating meaningful predictions of the unresolved IR spectra of moderately heavy complexes.…”

Section: Introductionmentioning

confidence: 99%

“…8 Following the approach of Ayllón et al, 4 our earlier work on this system reported the results of an essentially exact quantum simulation of the mid-and far-IR spectra, undertaken in order both to study the role of the dipole moment surfaces governing those spectra and to test the more recent MMSV mod and XC-3 potential energy surfaces. 5 The work of Ref. 5 showed that the contributions of the short-range terms in the semi-empirical dipole moment surface for 14 N 2 -Ar to the relative intensities of the features of the mid-IR spectrum are negligible, and that the induction contributions dominate the intensities.…”

Section: Introductionmentioning

confidence: 99%

“…5 The work of Ref. 5 showed that the contributions of the short-range terms in the semi-empirical dipole moment surface for 14 N 2 -Ar to the relative intensities of the features of the mid-IR spectrum are negligible, and that the induction contributions dominate the intensities. It also showed that the spectrum generated using the MMSV mod potential with the improved model dipole moment surface used there gave better agreement with experiment than did that calculated using the more recent XC-3 surface.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Dipole moment surfaces and the mid- and far-IR spectra of N2-Ar

Wang

McCourt

Roy

2000

The Journal of Chemical Physics

Self Cite

View full text Add to dashboard Cite

An improved theoretical long-range dispersion plus induction dipole moment surface for N 2-Ar is presented, and detailed numerical simulations are used to test its predictions against experimental far-IR and mid-IR spectra using two previously-reported potential energy surfaces. As was found in earlier work on the mid-IR spectrum using a pure induction dipole surface, the MMSV mod potential of Jäger et al. ͓J. Chem. Soc. Faraday Discuss. 97, 105 ͑1994͔͒ yields distinctly better agreement with both experiments than does the XC-3 potential of Dham et al. ͓J. Chem. Phys. 103, 8477 ͑1995͔͒. However, the new dipole surface yields slightly poorer agreement with certain features of the experimental mid-IR and far-IR spectra, which suggests that the existing theoretical values and derivatives with respect to the bond length of some of the permanent moment and ͑hyper͒polarizability properties of N 2 need improvement.

show abstract