H2N-CH(CH3)-C(=O)NH2
		Nitrogen
	Nuclear Quadrupole Coupling Constants
	in Alaninamide
	Nitrogen nqcc's in alaninamide and a best-fit (rs/ro) molecular structure were determined by Lavrich et al. [1].  Calculation of the nitrogen nqcc's was made here on this best-fit structure and on an ropt structure given by B3P86/6-31G(3d,3p) optimization.  These calculated nqcc's are compared with the experimental values in Tables 1 and 2.  Structure parameters are given in Table 3.  Calculated and experimental rotational constants are compared in Table 4.
	In Tables 1 and 2, subscripts a,b,c refer to the principal axes of the inertia tensor; subscripts x,y,z to the principal axes of the nqcc tensor.  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 the nitrogen efg's/nqcc's.
	Table 1. Amino 14N nqcc's in Alaninamide (MHz).  Calculation was made on the best-fit [1] and ropt  structures.     Best-Fit  ropt Expt. [1]     Xaa 1.719 1.439 1.368(4) Xbb 0.897 0.595 0.606(5) Xcc - 2.616 - 2.034 - 1.974 Xab 1.110 1.533 Xac 1.251 0.595 Xbc - 2.529 - 2.636   RMS 0.454 (34. %) 0.054 (4.1 %) RSD 0.030 (1.3 %) 0.030 (1.3 %)   Xxx 1.794 1.882 Xyy 2.578 2.642 Xzz - 4.372 - 4.524 ETA 0.179 0.168
	Table 2. Amido 14N nqcc's in Alaninamide (MHz).  Calculation was made on the best-fit [1] and ropt  structures.     Best-Fit  ropt Expt. [1]     Xaa 1.446 1.708 1.618(3) Xbb - 0.251 0.518 0.598(5) Xcc - 1.195 - 2.226 - 2.216 Xab 0.585 0.122 Xac - 1.148 - 0.871 Xbc 2.408 2.226   RMS 0.772 (52. %) 0.070 (4.7 %) RSD 0.030 (1.3 %) 0.030 (1.3 %)   Xxx 1.480 1.490 Xyy 2.018 2.124 Xzz - 3.498 - 3.615 ETA 0.154 0.175
	Table 3. Alaninamide.  Structure parameters (Å and degrees).    N  C,1,B1  C,2,B2,1,A1  C,2,B3,1,A2,3,D1,0  O,4,B4,2,A3,1,D2,0  N,4,B5,2,A4,1,D3,0  H,1,B6,2,A5,4,D4,0  H,1,B7,2,A6,4,D5,0  H,2,B8,1,A7,3,D6,0  H,3,B9,2,A8,1,D7,0  H,3,B10,2,A9,1,D8,0  H,3,B11,2,A10,1,D9,0  H,6,B12,4,A11,2,D10,0  H,6,B13,4,A12,2,D11,0 Best-Fit *       ropt B1=1.48284 B2=1.51962 B3=1.52768 B4=1.25784 B5=1.33077 B6=1.01668 B7=1.01657 B8=1.10213 B9=1.09363 B10=1.09581 B11=1.09590 B12=1.00976 B13=1.00781 A1=109.656 A2=109.349 A3=118.970 A4=117.226 A5=108.805 A6=109.265 A7=113.868 A8=109.737 A9=110.861 A10=109.852 A11=117.579 A12=117.318 D1=121.852 D2=167.405 D3=-21.102 D4=171.214 D5=-73.763 D6=-121.594 D7=175.760 D8=-64.135 D9=55.850 D10=-3.478 D11=-159.621  B1=1.4640073  B2=1.52378867  B3=1.53078929  B4=1.21834716  B5=1.35063777  B6=1.01434923  B7=1.01466118  B8=1.09813415  B9=1.09057229  B10=1.09408973  B11=1.09395509  B12=1.00950015  B13=1.00621127  A1=110.12776684  A2=111.43520268  A3=121.01736175  A4=114.71141281  A5=110.08718563  A6=110.48578466  A7=113.15106644  A8=109.97526796  A9=110.67739522  A10=110.50843693  A11=118.47598753  A12=119.15029805  D1=120.4281597  D2=165.60127299  D3=-15.29168762  D4=160.29119012  D5=-82.45345113  D6=-121.46899311  D7=175.01671191  D8=-65.1733097  D9=54.92649236  D10=-2.78705813  D11=-174.66751537   * Generated here from best-fit atomic coordinates given in Ref. [1].
	Table 4.  Alaninamide.  Rotational Constants (MHz).      ropt    Expt. [1] A 4954.2 4931.929(1) B 3157.2 3114.6022(8) C 2294.0 2297.2573(8)
	[1] R.J.Lavrich, J.O.Farrar, and M.J.Tubergen, J.Phys.Chem. A 103,4659(1999).
	Alanine		Acetamide		N-Acetylalainemethylester
	Formamide
	Table of Contents
	Molecules/Nitrogen
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						Last Modified 17 April 2015