N(CH3)2-C(=O)-CH3
		Nitrogen
	Nuclear Quadrupole Coupling Constants
	in N,N-Dimethylacetamide
	Calculation of the nitrogen nqcc tensor in N,N-dimethylacetamide was made here on a molecular structure given by HF/6-311++G(3df,3pd) optimization assuming Cs symmetry.  These are compared with the experimental nqcc's [1] in Table 1.  Structure parameters are given in Table 2.
	In Table 1, subscripts a,b,c refer to the principal axes of the inertia tensor; x,y,z to the principal axes of the nqcc tensor.  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 (percentage of the average of the magnitudes of the experimental nqcc's).  RSD is the calibration residual standard deviation of the B3PW91/6-311+G(df,pd) model for calculation of nitrogen nqcc's.
	Table 1.  14N nqcc's in N,N-Dimethylacetamide (MHz).  Calculation was made on the  HF/6-311++G(3df,3pd) structure.     Calc. Expt. [1]     14N Xaa 2.063 2.0927(19) Xbb - Xcc 7.128 7.1995(25) Xbb 2.533 2.5534 * Xcc - 4.596 - 4.6461 * |Xab| 0.019   RMS 0.036 (1.2 %)   RSD 0.030 (1.3 %)   Xxx 2.062 Xyy 2.534 Xzz - 4.596 ETA 0.103 Øz,c    0
	* Calculated here from experimental Xaa and Xbb - Xcc.
	Table 2.  N,N-Dimethyacetamide.  HF/6-311++G(3df,3pd) ropt heavy atom structure parameters (Å and degrees).  Complete structure is given here in Z-matrix format.   Point Group: Cs ropt  C(2)=O 1.1978 C(2)C(3) 1.5155 C(2)N 1.3551 NC(5) 1.4420 NC(6) 1.4465 C(3)C(2)=O 119.73 NC(2)=O 122.14 C(2)NC(5) 125.35 C(2)NC(6) 119.80
	Note:  On a structure with C1 symmetry given by HF/6-311+G(3df,3pd) optimization, calculated diagonal nqcc's are Xaa = 2.026, Xbb = 2.536, and Xcc = -4.562 MHz, for which RMS = 0.063 MHz (2.0 %).
	[1] M.Fujitake, Y.Kubota, and N.Ohashi, J.Mol.Spectrosc. 236,97(2006).
	Acetamide		N-Methylacetamide
	Table of Contents
	Molecules/Nitrogen
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						Last Modified 2 Feb 2011