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], Benedict and Pyler [5], and Demaison et al. [6].  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.  Ø (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 [5] and [6] are for the re structures on which calculations were made.     Calc. [5] Calc. [6] 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 Øz,u 68.94 68.96 Øu,ND 67.85 67.88 Øz,ND   1.09   1.08
	Table 2.  Nitrogen nqcc's in NH3 (MHz).  References [5] and [6] are for the re structures on which calculations were made.     Calc. Expt.     14N Xzz - 4.081 [5] - 4.08965 [2] - 4.080 [6] - 4.0924(9) [3]   - 4.080(3) [4]
	Table 3.  Ammonia structure parameters, re [5,6] (Å and degrees).    re [5]  re [6] NH 1.0124 1.0110 HNH 106.67 106.70
	Table 4. Atomic coordinates, re [5]. (More figures are shown than are significant.)     u (Å)   v (Å)   w (Å)   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] W.S.Benedict and E.K.Plyler, Canadian J.Phys. 35,1235(1957).
	[6] J.Demaison, L.Margulès, and J.E.Boggs, Chem.Phys. 260,65(2000).
	"The accurate determination of molecular equilibrium structures" K.L.Bak, J.Gauss, P.Jørgensen, J.Olsen, T.Helgator, and J.F.Stanton, J.Mol.Spectrosc. 114,6548(2001).   re(HN) = 1.0116 Å, 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 30 June 2008