NH3







 









Deuterium and Nitrogen


Nuclear Quadrupole Coupling Constants


in Ammonia


 








 


 





Deuterium and nitrogen quadrupole coupling in ammonia have been the subjects of numerous experimental and theoretical investigations.  Cited on this page are the publications of Cederberg [1], Hougen [2], Kukolich and Wofsy [3], Herman [4], Cazzoli et al. [5], Benedict and Pyler [6], and Demaison et al. [7].  Cederberg determined the diagonal components of the deuterium nqcc tensor.  Hougen, Kukolich and Wofsy, and Herman measured the nitrogen nqcc.  Benedict and Pyler and Demaison et al. report equilibrium molecular structures.

 








The complete deuterium and nitrogen nqcc tensors were calculated on the equilibrium structure of Benedict and Plyer, and on that of Demaison et al.  Calculated deuterium nqcc's are compared with the experimental values of Cederberg in Table 1.  In Table 2, the nitrogen nqcc's, calculated and experimental, are compared.  Structure parameters and atomic coordinates are shown in Tables 3 and 4, respectively.

 








 








Coordinate Systems

The subscripts u,v,w refer to the coordinate axes defined in Table 4.  The u-axis is along the threefold symmetry axis.  The nqcc's given below with these subscripts are those for the H atom in the uv-plane.

The subscripts x,y,z refer to the principal axes of the nqcc tensor.  The y-axis is chosen coincident with the w-axis.  (degrees) is the angle between its subscripted parameters.  ETA = (Xxx - Xyy)/Xzz.

 








RMS is the root mean square difference between calculated and experimental diagonal nqcc's.  RSD is the residual standard deviation of calibration of the model for calculation of the nqcc's.

 








   









Table 1.  Deuterium nqcc's in ND3 (kHz).  References [6] and [7] are for the re structures on which calculations were made.

   










Calc. [6]
Calc. [7]
Expt. [1]

 









2H Xuu
- 93.1
- 94.0
- 96 *



Xvv
200.0
202.0
207

  Xww - 106.9 - 108.0 - 111


Xuv - 132.5
133.6



 









RMS
5.0 (3.6 %)
3.6 (2.6 %)




RSD
1.1 (0.9 %)
1.1 (0.9 %)



 









Xxx - 144.1 - 145.4




Xyy - 106.9 - 108.0




Xzz
251.0
253.3




ETA - 0.148 - 0.148




z,u
68.94
68.96




u,ND
67.85
67.88




z,ND
  1.09
  1.08



 









 








* Cazzoli and Puzzarini [8], Xcc = -94.5(12) kHz.


 









 









   







Table 2.  Nitrogen nqcc's in NH3 (MHz).  References [6] and [7] are for the re structures on which calculations were made.

   








Calc.
Expt.
   







14N Xzz - 4.081 [6] - 4.08965 [2]



- 4.080 [7] - 4.0924(9) [3]

 



-
4.080(3) [4]





- 4.08984(70) [5]

 







 








 








 

 
Table 3.  Ammonia structure parameters, re [6,7] ( and degrees).
 




 re [6]  re [7]





NH 1.0124 1.0110

HNH 106.67 106.70


 
















Table 4. Atomic coordinates, re [6].
(More figures are shown than are significant.)
 









  u ()
  v ()
  w ()
 







H - 0.266755
0.937077
0.0

H - 0.266755 - 0.468538 0.811532

N
0.114324
0.0
0.0


 








 








[1] J.Cederberg, J.Mol.Spectrosc. 77,102 (1979).

[2] J.T.Hougen, J.Chem.Phys. 57,4207(1972).

[3] S.G.Kukolich and S.C.Wofsy, J.Chem.Phys. 52,5477(1970).

[4] G.R.Herman, J.Chem.Phys. 29,875(1958).

[5] G.Cazzoli, L.Dore, and C.Puzzarini, A&A 507,1707(2009).

[6] W.S.Benedict and E.K.Plyler, Canadian J.Phys. 35,1235(1957).

[7] J.Demaison, L.Marguls, and J.E.Boggs, Chem.Phys. 260,65(2000).

[8] G.Cazzoli and C.Puzzarini, 71st ISMS, 2016:  In ND3, eQq (N) = -4.08258(95) MHz.


 









"The accurate determination of molecular equilibrium structures" K.L.Bak, J.Gauss, P.Jrgensen, J.Olsen, T.Helgator, and J.F.Stanton, J.Mol.Spectrosc. 114,6548(2001).   re(HN) = 1.0116 , re(HNH) =  107.25o.  Calculation on this structure gives, for 14N, eQq = -4.147 MHz.

 








 








CD3F CD3Cl CD3Br CD3CN

HCC-CD3 BH3NH3 NF3 NCl3

(CH3)3N NF2H NFH2


 








 








Table of Contents




Molecules/Deuterium




Molecules/Nitrogen




 








 













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Last Modified 8 Jan 2011