Vibronic structure and photodissociation dynamics of the Ã state of jet-cooled ammonia

Bach, Andreas; Hutchison, J. Matthew; Holiday, Robert J.; Crim, F. Fleming

doi:10.1063/1.1471908

Cited by 40 publications

(33 citation statements)

References 45 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…For the dynamics simulation of the photodissociation of ammonia, a property that is probably more important is the barrier height. The classical barrier height relative to energy of the planar NH 3 (Ã 1 A 2 ) minimum given by the analytical function is 0.22, and 0.07 eV lower than the best literature value of 0.29 eV [26].…”

Section: Discussionmentioning

confidence: 81%

“…The solid line is U 11 , and the dashed line is U 22 functionality. The dissociating N-H bond distance at the optimized saddle point with the current analytical function is slightly shorter than the best available value of 1.298 Å [26] by 0.009 Å, while the other two N-H bond distances are very close to the literature values [26]. For the dynamics simulation of the photodissociation of ammonia, a property that is probably more important is the barrier height.…”

Section: Discussionmentioning

confidence: 84%

“…The use of Eq. (8) [25], but closer to the best available theoretical value of 5.902 eV calculated by Bach et al [26]. We will use the value of 5.923 eV.…”

Section: Stationary-point Datamentioning

confidence: 99%

“…Theoretical state-specific CASSCF as well as experimental (or best-estimate theoretical) data [20][21][22][23][24][25][26][27][28][29][30][31] are presented in Tables 4 and 5. The data in the tables serve two purposes, namely (1) they are used to constrain the fitted PESs to reproduce the experimental …”

Section: Stationary-point Datamentioning

confidence: 99%

See 3 more Smart Citations

Improved direct diabatization and coupled potential energy surfaces for the photodissociation of ammonia

Valero

Truhlar

2007

Theor Chem Account

View full text Add to dashboard Cite

Diabatic potential energy surfaces are a convenient starting point for dynamics calculations of photochemical processes, and they can be calculated by the fourfold way direct diabatization scheme. Here we present an improved definition of the reference orbital for applying the fourfold way direct diabatization scheme to ammonia. The improved reference orbital is a geometry-dependent hybrid orbital that allows one to define consistent dominant configuration lists at all geometries important for photodissociation. Using diabatic energies calculated with the new reference orbital and consistent dominant configuration lists, we have refitted the analytical representations of the ground and the first electronically excited singlet-state potential energy surfaces and the diabatic coupling surface. Improved functional forms were used to reproduce the experimental dissociation energies and excitation energies, which will be important for subsequent simulations of photochemical dynamics. We find that the lowestenergy conical intersection point is at 5.16 eV, with C 2v symmetry. Electronic supplementary materialThe online version of this article

show abstract

Section: Discussionmentioning

confidence: 81%

Section: Discussionmentioning

confidence: 84%

“…The use of Eq. (8) [25], but closer to the best available theoretical value of 5.902 eV calculated by Bach et al [26]. We will use the value of 5.923 eV.…”

Section: Stationary-point Datamentioning

confidence: 99%

Section: Stationary-point Datamentioning

confidence: 99%

See 2 more Smart Citations

Improved direct diabatization and coupled potential energy surfaces for the photodissociation of ammonia

Valero

Truhlar

2007

Theor Chem Account

View full text Add to dashboard Cite

show abstract

“…The photolysis of ammonia is a prototypical example of dissociation through a conical intersection between two electronic states, and its study has shaped many ideas about the dissociation involving a conical intersection [20][21][22][23][24][25][26][27][28][29]. The adiabatic decomposition of electronically excited NH 3 (Ã 1 A 00 2 ) produces a hydrogen atom and an electronically excited fragment NH Ã 2 (H þ NH 2 ( 2 A 1 )), and the nonadiabatic decomposition *Corresponding author.…”

Section: Introductionmentioning

confidence: 99%

Vibrationally mediated photodissociation of ammonia: product angular distributions from adiabatic and nonadiabatic dissociation

Hause¹,

Yoon²,

Crim³

2008

Molecular Physics

View full text Add to dashboard Cite

Velocity map ion imaging of H atoms from the photodissociation of vibrationally excited ammonia molecules measures the angular distribution of the fragments from dissociation of the excited state symmetric N-H stretch (1 1 ) and the antisymmetric N-H stretch (3 1 ). For the symmetric stretching state, the high rotational energy NH 2 fragments recoil with an angular distribution whose maximum is parallel to the polarization direction of the lasers, and the low rotational energy fragments recoil with a perpendicular angular distribution. This behavior is similar to that observed for photodissociation from the origin (0 0 ) but with a larger range in the anisotropy parameter ( 2 ) caused by additional alignment in the two-photon excitation. The dissociation through the excited state antisymmetric N-H stretch produces primarily electronically excited products (NH Ã 2 þ H). The initial alignment of molecules in the antisymmetric stretching state is a combination of perpendicular alignment from the vibrational excitation and parallel alignment from the electronic excitation. Fitting the more complicated angular distributions for the NH Ã 2 channel requires a higher order term ( 4 ) that also varies with recoil energy to describe the angular distribution.

show abstract

Competition between Metal-Amido and Metal-Imido Chemistries in the Alkaline Earth Series: An Experimental and Theoretical Study of BaNH

2006

View full text Add to dashboard Cite

The pure rotational spectrum of BaNH in its X 1 Σ + ground electronic state has been recorded using millimeter/submillimeter direct absorption methods; data for the deuterium and barium 137 isotopomers have been measured as well. The molecules were produced by the reaction of ammonia or ND3 and barium vapor in the presence of a dc discharge. Transitions arising from the ground vibrational state and the excited vibrational bending (01 1 0) and heavy atom stretching (100) modes were measured. The rotational spectrum indicates a linear structure, with B0(BaNH) ) 7984.549 MHz and B0(BaND) ) 7060.446 MHz. An rm (1) structure has been determined, yielding r(BaN) ) 2.077 ( 0.002 Å and r(NH) ) 1.0116 ( 0.0006 Å. Density functional calculations using an extensive Slater-type basis set with inclusion of scalar relativistic effects gives geometrical parameters and vibrational frequencies for BaNH in excellent agreement with those determined by experiment. The molecular orbital and natural bond order analyses of the BaNH wave function show Ba-N π bonds formed by electron donation from the formally filled N 2p orbitals of the imido group to the empty Ba 5d orbitals. The multiple bonding between Ba and N stabilizes the linear geometry and, along with the relative ease of oxidation of the Ba atom, favors formation of the metal-imido species over that of the metal-amido species that have been found from similar studies with Mg, Ca, and Sr atoms in this group.

show abstract

Vibronic structure and photodissociation dynamics of the Ã state of jet-cooled ammonia

Cited by 40 publications

References 45 publications

Improved direct diabatization and coupled potential energy surfaces for the photodissociation of ammonia

Improved direct diabatization and coupled potential energy surfaces for the photodissociation of ammonia

Vibrationally mediated photodissociation of ammonia: product angular distributions from adiabatic and nonadiabatic dissociation

Competition between Metal-Amido and Metal-Imido Chemistries in the Alkaline Earth Series: An Experimental and Theoretical Study of BaNH

Contact Info

Product

Resources

About